- Current Issue
- Online First
- Downloaded Archive
-
HUANG Zhi, ZHOU Furong, CHEN Juan, JIANG Lizhong, ZHOU Wangbao, QI Jingjing
2024(2):263-272, DOI: 10.13409/j.cnki.jdpme.20231025001
Abstract:
To rapidly assess the extent of seismic damage in mega composite frame structures, thisstudy introduced a multi-parameter seismic damage prediction method utilizing Improved Pelican Opti-mization Algorithm (IPOA). Five models with different parameters were developed, and dynamic re-sponse data for the structures were obtained through shaking table tests and nonlinear time-history analyses using finite element (FE) software. Structural damage indices were quantified to assess the ex-tent of damage. Additionally, the traditional Pelican Optimization Algorithm (POA) was enhanced byincorporating K-means clustering optimization and inertia weight adaptive optimization strategy. Basedon the data from shaking table tests and FE analyses, the accuracy of structural damage predictions us-ing different input parameter combinations was compared. A rapid prediction model using an intelli-gent algorithm was constructed to reflect the nonlinear relationship between structural parameters andits damage. Finally, the model's predictions were compared and verified against the seismic damageextent from shaking table tests on a 1/15 scale model. The results indicated that: (1) The IPOA modelexhibited superior accuracy and generalization capability compared to other algorithm models; (2) Themaximum inter-story drift angle showed the highest correlation with structural damage. The introduc-tion of additional input parameters that affected structural damage could enhance the model's predic-tion accuracy and its generalization capability; (3) The predicted structural damage indices exhibited anerror of less than 10% compared to the experimental results, and the predicted levels of structuraldamage aligned with the experimental results. The proposed rapid prediction model can effectively andaccurately predict structural damage indicators.
-
WANG Li, PAN Qiren, ZHOU Xiaofu, YANG Xijuan, TANG Zhiyong
2024(2):273-282, DOI: 10.13409/j.cnki.jdpme.20231130005
Abstract:
Currently, the design of railway bridges is gradually transitioning from the allowable stressmethod to the limit state method. However, the Code for Design on Railway Bridge and Culvert(Limit State Method) (Q/CR 9300-2018) does not account for the combined effects of seismic actionsand variable factors such as temperature, posing significant challenges for seismic design for bridges inareas of extreme cold and high seismic intensity. In order to promote bridge resistance to externalloads in a more cost-effective way, the partial coefficient of the optimal seismic design condition loadcombination was determined by target reliability indices, thereby optimizing the seismic design standardsin current bridge design codes. A probability model for temperature effects on a bridge in cold regionswas established. The distribution characteristics of the effects of earthquake and ambient temperaturewere explored using the Ferry Borges load combination theory. Expressions of the load factor ofearthquake and temperature effects were established using JC method and multi-hazard load factor designmethod (MH-LRFD). Taking a practical bridge engineering project as an example, the failureprobabilities of a bridge under earthquake, temperature, and their combined actions were explored respectively.The results showed that both the temperature internal force response caused by ambienttemperature and the variation in properties of the bridge's main components significantly affected itsfailure probability. For extreme cold regions with significant temperature variations, ignoring ambienttemperature in the current codes would significantly underestimate the failure probability under seismicactions. The proposed F-J-M (Ferry Borges-JC-MH-LRFD) method can be used to calculate the com bined coefficients for earthquake and temperature actions, providing a necessary theoretical basis forthe seismic design of bridges in extreme cold regions.
-
2024(2):283-292, DOI: 10.13409/j.cnki.jdpme.20230907004
Abstract:
Extreme rainstorms often cause great damage to immovable cultural relics. Analysis on thepost-disaster damage can provide crucial insights for effective preventive measures. Through compil-ing post-disaster survey data from 188 immovable cultural relics affected by the "7·20" rainstorm inHenan Province in 2021, different characteristics of damage were analyzed. Damage types were cate-gorized into: slow erosion and deterioration caused by rainstorm runoff and water immersion, as wellas sudden destruction due to flood impact and debris flow. In addition, accumulated rainfall was usedto characterize the hazard intensity of rainstorm disasters, and a vulnerability curve model based onLognormal probability distribution function was constructed. The vulnerability characteristics of immovable cultural relics were comprehensively analyzed, considering structural materials, buildingscale, and preservation state. The results showed that brick-soil structure relics were more vulnerablethan brick-wood and brick-stone structures, with a higher probability of serious damage when rainfallexceeded 100 mm. Brick-wood and brick-stone structure relics had a higher probability of serious dam -age when rainfall exceeded 340 mm. Cultural relics with construction areas under 100 m2 were particu-larly vulnerable, experiencing severe damage during extreme rainstorms. Cultural relics in poor preser-vation states were more vulnerable and had a higher probability of serious damage even at very lowrainfall intensity (less than 25 mm).
-
DAI Junhao, YANG Shigang, FANG Qin, YANG Ya
2024(2):293-300, DOI: 10.13409/j.cnki.jdpme.20230317007
Abstract:
Lowering the temperature of hydrogen allows for higher density storage, effectively enhancingstorage and transportation efficiency. To investigate the influence of hydrogen storage temperatureon the risk of leakage and explosion incidents at hydrogen refueling stations, FLACS software wasused to analyze the diffusion and explosion of hydrogen following a leakage from a tube trailer withinthe station under different storage temperatures (50 K, 100 K, 200 K, and 300 K). The study resultsindicated that with the decrease in hydrogen storage temperature, the time for the combustible gascloud to stabilize, its diffusion range, and the cryogenic burn areas all increased after a high-pressurehydrogen jet hit the explosion-proof wall. Meanwhile, the maximum explosion overpressure and explosionhazard distance initially increased and then decreased. The distance for minor cryogenic burns at astorage temperature of 50 K was nearly twice that at 100 K and seven times that at 200 K, with severecryogenic burns covering the largest areas. The peak overpressure from cloud explosions at 100 K wasnearly triple that of a standard-temperature hydrogen explosion, with the largest hazard area. At a storagetemperature of 200 K, the time to reach peak explosion overpressure was the shortest, whereas at50 K, it was the longest.
-
2024(2):301-312, DOI: 10.13409/j.cnki.jdpme.20230223003
Abstract:
The study aims to analyze the reliability of water inrush disaster prevention at faces in deep-ly buried karst tunnels under high ground stress, high-pressure and water-rich conditions. Built uponexisting research and the geological environment, a 3D outburst prevention mechanism for the tunnelfaces, primarily based on shear failure, was constructed using the upper bound analysis method. Anenergy equation for the water inrush failure process was established based on the principle of virtualwork rate. The Hoek-Brown strength criterion was used to determine the upper limit solution for thesupport pressure required to prevent water inrush in tunnel faces under high ground stress, high-pressure, and water-rich conditions. Under the state of extreme failure, a limit state equation was estab-lished based on the support pressure applied to the tunnel faces and the surrounding rock pressure atthe time of water inrush failure. A reliability model for outburst prevention at the faces of deeply buriedkarst tunnels was established. To determine the likelihood of water inrush disasters at tunnel faces,the response surface method (RSM) was applied. The effects of horizontal ground stress, water pres-sure in dissolution cavities, rock mass strength parameters, and tunnel diameter on support pressureand potential failure length were analyzed. The minimum support pressure required to prevent waterinrush disasters in deeply buried karst tunnels under different allowable failure probabilities and themaximum damage length that could be resisted under limited support effectiveness was provided. Ap-plied to practical engineering cases and compared with existing studies and field results, the findingsconfirm the effectiveness of the calculated results, offering theoretical guidance for preventing outburstproblems in similar deeply buried karst tunnels in the future.
-
CHEN Yuan, LIU Ran, LUO Changwei, SUN Tao, QIN Zhuangen, HOU Zhengjun, YANG Baoquan
2024(2):313-321, DOI: 10.13409/j.cnki.jdpme.20231030004
Abstract:
Rockfall disasters frequently occur in the tailrace branch tunnel slope of a hydropower sta-tion, leading to partial damage to the original passive protection network and posing severe risk to thesafety of the tunnel exit area during the construction and operation period. It is very urgent and neces-sary to repair and reinforce the original passive protection network. Given the steep and complex landform, the rockfall sources could not be identified through manual survey. Therefore, high-precisionUAV aerial imagery was utilized to preliminarily identify four potential hazard areas. Rockfall softwarewas used for trajectory simulation calculations. By comparing and analyzing the simulated results withthe observed rockfall landing positions and the distribution of the threatened areas, two rockfall sourc-es were identified through inverse analysis. Based on this, by analyzing the movement characteristicsof these sources, a review was conducted on the reasons behind the insufficient original protection ca-pacity. It was discovered that the primary causes for rockfall disasters were the low energy level and in-adequate height of the existing protection network. Two schemes were proposed to enhance the net-work's energy level and height: in-situ repair and heightening reinforcement. The analysis results indi-cated that both schemes could effectively reduce the area threatened by rockfalls, lower the rockfall oc-currence rate, and improve movement characteristic parameters. Among them, the heightening rein-forcement scheme had a more significant protection effect, with all rockfalls being intercepted. Themaximum values of rockfall's kinetic energy and bouncing height were reduced by 66.02% and69.64%, respectively. The scheme of in-situ repair and reinforcement of the network's damaged sec-tions would be more logical and scientific when the actual site conditions and rockfall simulation resultswere taken into consideration. The research results provide a scientific basis for rockfall protection mea-sures of this project and serve as a reference for similar rockfall analysis and engineering design.
-
LIU Hongjun, WU Wenyu, GENG Lin, LIU Liang, ZHANG Guoliang, SUN Wenyu, YU Peng
2024(2):322-332, DOI: 10.13409/j.cnki.jdpme.20230529005
Abstract:
Rainfall is the primary trigger for landslides. With China's disaster prevention efforts changingfrom post-disaster relief to pre-disaster prevention, and from disaster loss reduction to disaster riskmitigation, it is crucial to understand the triggering mechanisms for rainfall-induced disasters and establisheffective early warning systems for geological disaster prevention and mitigation. To addressthe stability issues of rainfall-induced landslides in fully weathered granites, shear tests on in-situ soils with different moisture contents and large-scale physical similarity model tests were carried out in Qingdao'sLao Mountain area as an example. The slope's response to rainfall was revealed, the relationshipbetween the stability of fully weathered granite landslides and rainfall was explored, and relevantquantitative formulas were fitted. Additionally, ABAQUS was used to establish a three-dimensionalflow-solid coupled numerical model for the slope, validating the equations through the strength reductionmethod. The research results showed that: (1) Rainfall-induced fully weathered granite landslidesfailure progressed through four stages: infiltration and erosion → surface deformation → damage deepening overall instability. The slope exhibited the phenomena of "drum-like bulge" and "sheet-likeslipping" during the deformation period, and ended up with a translational slipping. (2) The slope's responseto rainfall infiltration showed spatial variability, with greater rainfall intensity leading to fasterincreases in moisture content and pore pressure. (3) Based on the experimental results, formulas describingthe relationship between landslide moisture content, safety factors, and rainfall intensity andduration were derived. Numerical simulation confirmed the accuracy of these formulas with minor deviation,accurately describing the quantitative relationship between landslide stability and rainfall. Theresults of the study provide insights on early warning and prevention strategies for landslides in areaswith similar strongly to fully weathered granite.
-
LI Yuxue, ZHENG Qianhui, LI Haiyun
2024(2):333-342, DOI: 10.13409/j.cnki.jdpme.20221102002
Abstract:
The cantilevered roofs of Fujian circular Tulou are structures that are sensitive to winds, lo-cated in China's typhoon-prone areas. In order to improve the structures' resistance to wind disastersand ensure its wind-resistant safety, CFD numerical simulation was conducted to study the wind loaddistribution characteristics on the roofs. Aerodynamic measures to enhance wind resistance were pro-posed. The results showed that wind pressure on the windward side of the roofs was relatively large,and the absolute wind pressure coefficients at the ends of both the inner and outer cantilevered roofs,which were sensitive to wind loads, were the largest, reaching 1.5 and 0.75, respectively. The addi-tion of vertical or corrugated wind deflectors at the ends of the outer cantilevered roofs could mitigatethe wind pressure on these sensitive parts to a certain extent. Generally, corrugated wind deflectorshad a better effect on unloading wind pressure than their vertical counterpart. For corrugated wind de-flectors, when their relative height h/Hj=0.05 (h being the height of the wind deflector and Hj beingthe distance from the ground to the roof ridge), inclination angle θ = 45°, and corrugated arc radiusR=5.5 m, the wind pressure unloading effect on the roof surface was the best. The wind pressure co-efficients at the ends of both the inner and outer cantilevered roofs were reduced by 40.1% and 54%,respectively. The corrugated design of the wind deflectors effectively blocked incoming wind flow tothe cantilevered roofs, causing vortices formed by air flow impact to shift from the roof ends to the de-flector surface. Furthermore, the corrugations reduced the intensity of air flow vortices on the surfacesof both inner and outer cantilevered roofs, thereby efficiently unloading the wind load.
-
ZHAO Xu, YUAN Yun, LI Ruohan, HUANG Jingqi, YU Zhaoyuan
2024(2):343-352, DOI: 10.13409/j.cnki.jdpme.20221117002
Abstract:
In order to explore the key factors that affect the damping performance of tunnels with dampinglayers, a finite element numerical model for such tunnels was established. The model's reliabilitywas verified by comparing with results from shaking table tests. By changing the design parameters ofthe damping layer and surrounding rock conditions, and analyzing the principal strain, relative deformationrate, and plastic zone of the tunnel structure, the layer's damping effects under different param eters were studied. The results showed that the transfer function of the tunnel acceleration response decreasedwithin the frequency range of 15~30 Hz after the installation of the damping layer. It indicatedthat the damping layer reduced the transmission of seismic wave energy to the tunnel by absorbing the high-frequency components of the seismic waves, thereby reducing the tunnel's seismic response. Parameter
analysis indicated that a damping layer with a lower elastic modulus and greater thickness hada more pronounced damping effect. However, this also led to an increase in the relative deformationrate of the tunnel structure. Compared with increasing the thickness of the damping layer, reducing itselastic modulus could improve its damping effect more significantly. The damping layer was more effectivein hard surrounding rock than in soft surrounding rock.RUAN Xinxin, FAN Yingfei, LIU Zhangjun, JIANG Yunmu
2024(2):353-361, DOI: 10.13409/j.cnki.jdpme.20221102005
Abstract:
Based on the earthquake scenarios, a dimension-reduction model capable of predicting andsimulating the stochastic ground motion acceleration process was developed. Firstly, 1766 strong mo-tion records were selected and grouped according to fault types and site classification. Parameters ofevolutionary power spectrum (EPS) for each group were identified. Secondly, based on the parametersfor earthquake scenarios and the EPS, a Gaussian process regression model (GPRM) was trained.Meanwhile, the K-fold cross-validation method was adopted to verify its prediction effectiveness andaccuracy. Finally, using the spectral representation method of non-stationary random processes and in-corporating the concept of dimension reduction for random functions, the dimension reduction simula-tion of stochastic ground motion was achieved under predefined earthquake scenarios. Numerical examples showed that the predicted samples were consistent with the measured records in terms of fre-quency spectrum, peak values, and duration of strong motion, which verified the suitability of the pro-posed methodology in engineering applications. The research provides reasonable artificial ground mo-tion data for target areas, and lays a foundation for random seismic response analysis and reliabilityevaluations of engineering structures.
XIONG Zhongming, XIONG Junlong, WANG Zekun, CHEN Xuan
2024(2):362-371, DOI: 10.13409/j.cnki.jdpme.20221209002
Abstract:
To carry out structural damage analysis on structures under special geological conditions, afive-story frame structure spanning the f4 ground fissure in Xi'an was taken as the research object.Based on the results from shaking table tests and ABAQUS finite element analysis, a BP neural networkmodel was trained. A two-parameter damage model combining deformation and energy was em ployed to calculate structural damage index. The weighted coefficient method was used to carry outthe damage prediction analysis of components, floors, and structures, providing evaluations of structuraldamage under different seismic impacts. The results showed that the structure on the ground fissuresite exhibited a significant hanging-wall/footwall effect, with the first layer being the weak layer.The BP neural network's damage prediction values closely aligned with the finite element calculation values across different conditions. The maximum prediction errors for components, inter-layer, andoverall structural damage indices were 8.86%, 5.66%, and 7.57%, respectively.
ZHANG Hanwen, JIANG Liangwei, DU Meiling, GE Xuejun, YANG Yun
2024(2):372-380, DOI: 10.13409/j.cnki.jdpme.20221115003
Abstract:
The selection of the most unfavorable state in the overall stability calculation of gravity re-taining walls has an important influence on seismic design. Shaking table model tests were used to re-veal the differences in seismic earth pressure values at three critical seismic moments for retainingwalls, namely, peak acceleration, peak outward rotation of the wall, and peak displacement at the topof the wall. Also, an evaluation of the envelope method, commonly used to select values at the peakearth pressure moment, was conducted. Based on the seismic response calculations of gravity retaining walls by the ABAQUS finite element model, the differences in earth pressure values at the back ofthe wall and the overall stability calculation results at each critical moment were analyzed, and themost unfavorable state in seismic stability calculation was proposed. Research showed that: (1) Withthe increase of peak ground acceleration and wall height, the seismic earth pressure at the three criticalmoments all showed a transition from a non-linear distribution to an approximately equilateral triangu-lar pattern. The combined earth pressure and the height of its action point were, on average, 49% and18% greater, respectively, than those in the current seismic design codes. (2) Due to the inability ofpeak envelope method to reflect the active/passive state of wall-soil motion and the seismic wave prop-agation delay, the earth pressure values near the top of the wall were overly high, and the combinedseismic earth pressure was twice as large as that at the critical moments, with the action point about25% higher. (3) The anti-slide stability coefficient at the moment of peak wall outward rotation was14%~33% smaller than the other two, and the sensitivity to attenuation was more obvious with theincrease of peak ground acceleration. Therefore, selecting the critical moment of peak wall outward ro-tation as the most unfavorable state in seismic stability calculation is deemed to achieve a balance be-tween structural safety and cost-effectiveness.
2024(2):381-388, DOI: 10.13409/j.cnki.jdpme.20221209001
Abstract:
The interaction between concrete and steel tubes in concrete-filled steel tube (CFST) trans-mission towers makes their seismic vulnerability different from that in ordinary concrete transmissiontowers. To compare and study these differences, the article examined the interaction between steeltubes and core concrete from a material constitutive model perspective. It used finite element softwareOpenSees to establish a model for the CFST transmission tower and analyzed its structural response.Incremental dynamic analysis was then applied to delineate vulnerability curves under various condi-tions, including frequent, design basis, rare, and extremely rare earthquakes. Furthermore, the quan-titative influence of the first cycle spectral acceleration on the failure probability of CFST transmissiontowers was assessed. The results of seismic vulnerability were compared with those of ordinary transmission towers. Findings indicated that CFST transmission towers were less vulnerable to severedamage or collapse under the actions of frequent, design basis, rare, and extremely rare earthquakes.The first cycle spectral accelerations were mostly between 1.0g~1.4g. With the increase in earthquakeintensity, the seismic performance of CFST transmission towers became worse than that of ordinarytransmission towers.
LI Yumei, WANG Guangyong, DAI Lin
2024(2):389-395, DOI: 10.13409/j.cnki.jdpme.20220815002
Abstract:
Reinforced concrete (RC) slabs are among the most vulnerable structural components todamage in fires, necessitating the post-fire evaluation of their load-bearing capacity and subsequent re-inforcement. A finite element model for analyzing the post-fire mechanical performance of RC slabswas proposed. In this model, the variations in material constitutive relations during heating, cooling,and post-fire stages were considered. The impact of concrete protective layer spalling on temperaturedistribution and mechanical properties of the slabs under high temperatures was also taken into consid-eration. Building on this model, another finite element model for evaluating the load-bearing perfor-mance of RC slabs reinforced after fire exposure was also proposed. Both models employed element birth-death technology to simulate concrete spalling under high temperatures and post-fire reinforce-ment. The models could be used to evaluate the post-fire mechanical performance of reinforced RCslabs. The analysis revealed significant reductions in the post-fire load-bearing capacity of RC slabs,with noticeable residual deflection; however, reinforcement was able to substantially restore this capac-ity.
2024(2):396-403, DOI: 10.13409/j.cnki.jdpme.20221208004
Abstract:
In order to address common issues with composite wall panel joints, such as the inflamma-bility and easy detachment of insulation boards, while ensuring their seismic performance, a new typeof ceramisite concrete T-shaped composite wall panel joints integrating load-bearing capabilities withthermal insulation was presented. The joints featured a unique sandwich-structured construction thatoffered several advantages. They were eco-friendly and energy-efficient, lightweight but strong, withgood mechanical properties and a reliable insulation system connection. They could also prevent fires.The hysteresis behavior, failure mechanisms, load bearing and deformation capacities, ductility, ener-gy dissipation, and damage of the T-shaped composite wall panel joints were studied through seismictests. The results showed that the sequence of damage in the integrated composite wall panel jointswas from the web, to the flange, and finally to the core area of the joint. Areas of weakness mainly oc-curred at the foot of the web, where the concrete was cracked or crushed and the reinforced bars werestretched or bent. The joint core area demonstrated strong resilience with ample safety margins. Thejoints were in line with the design requirements of "strong joints, weak components" and policies for wall panel innovation. With a ductility coefficient greater than 3, the safety performance of the jointswas good. Through the damage index assessment, the working states of the specimens at each stagewere identified.
ZHAO Haisong, ZHANG Le, WU Kai, WEI Anhui, XIANG Bo, SHAO Jiang, ZHANG Junyun
2024(2):404-414, DOI: 10.13409/j.cnki.jdpme.20221111002
Abstract:
Under the influence of lateral wall resistance, the main sliding direction of a bedding slopedeviates from the direction of rock layer orientation, exhibiting typical features in its deformation andfailure mechanisms. Taking a bedding slope in the Mabian River of Sichuan basin as a case study, wesummarized the slope deformation characteristics of different areas based on its engineering geologicalconditions. Then, we analyzed the evolution mechanism of bedding slope failure considering lateralwall resistance and the failure boundary conditions. Finally, the three-dimensional stability of beddingslope under the effect of lateral wall resistance was analyzed, and the effects of various influencing factors were studied by comparing the stress differences experienced when the main sliding direction devi-ated from or aligned with the rock layer orientation. The results showed that: (1) Considering lateralwall resistance, the deformation of a bedding slope could be categorized into an unstable sliding zone,landslide zone, and stable zone. The landslide zone included a sliding zone and a creep-slippage zone.After sliding, the rock mass in the sliding zone disintegrated and weathered into broken and block soil,and the creep-slippage zone experienced only deformation and cracking under the effect of lateral wallresistance. (2) After rock mass deterioration and the appearance of free surface at its forefront, the bed-ding slope presented a bedding-plane free-fall-backward failure with sliding in the lower part and creepcrackingin the middle part. The boundary of the sliding zone was controlled by the leading edge andthe free face of the lateral wall, with its sliding distance being similar to that of the undercut segmentof gully sidewall. The lateral wall was transformed from a joint face into a compression zone in parts ofthe creep-slippage zone, increasing the lateral wall resistance and resulting in a higher stability than thecritical instability state. The boundary between the creep-slippage zone and the stable zone wascracked due to the thinning of the sliding mass thickness and the lateral wall resistance. (3) A formulafor the stability coefficient of the bedding slope considering side-wall resistance was developed, aswell as a conversion equation between the rock layer dip angle, slip surface dip angle α, and the angle β between the main slip direction and the rock layer orientation. The results showed that the larger the β and the friction coefficient of lateral wall, the greater the contribution of the resistance to the stabilityof bedding slopes.
ZOU Xinjun, HU Jianfeng, YANG Zijian
2024(2):415-425, DOI: 10.13409/j.cnki.jdpme.20221202001
Abstract:
Offshore wind turbine foundations are subjected to not only vertical forces (V), such as deadweight, but also horizontal loads (H) under the influence of currents, waves, and wind. In order to ex-plore the load-bearing behavior under VH combined loading of a new type of offshore wind turbinecomposite foundation, which was composed of a single pile and suction bucket in sand over clay soildeposits, a series of indoor V-H combined loading model tests for the pile-bucket composite founda-tion were independently designed and completed. Load-displacement curves and bending moment dis-tribution curves for the pile-bucket composite foundation under different combined parameters were ob-tained, and V-H bearing capacity envelopes were drawn. Based on this, ABAQUS was used to estab-lish a three-dimensional numerical analysis model for pile-bucket composite foundation in sand overclay soil deposits. After model validation and parameter analysis, the effects of sand layer thickness,bucket diameter, bucket height, and loading height on its bearing characteristics were investigated. Asimplified formula for calculating the bearing capacity of the pile-bucket composite foundation was de-veloped. The results showed that the pile-bucket composite foundation could significantly improve thehorizontal bearing capacity of the pile by about 30%~90%. Moreover, increasing the bucket diameterwas more efficient in improving its horizontal bearing capacity than increasing the bucket height. Forthicker upper sand layers, an optimal pre-applied vertical load existed that maximized the horizontalbearing capacity of the composite foundation, and it varied in the range of 0.4~0.7 Vult under differentloading cases.
XIAO Tianxiang, GAO Wenhua, ZHANG Zongtang, SHEN Ziyu, HE Yu, ZHOU Zel
2024(2):426-433, DOI: 10.13409/j.cnki.jdpme.20221030001
Abstract:
To achieve the recycling of mask waste, they were used in the reinforcement of coal gangueroadbeds. By conducting a large-scale dynamic triaxial test under cyclic loading with different reinforce-ment methods and mask contents, the feasibility and influencing factors of mask reinforcement in coalgangue roadbeds were investigated, and the reinforcing effect of masks in roadbeds was studied. Theresults showed that: (1) Coarse-grained soil fillers for roadbeds reinforced with masks in coal ganguedemonstrated effective reinforcement; (2) Different reinforcement methods, fiber size, mask cutting di-rection, and mask content in roadbeds could affect the effectiveness of reinforcement; (3) Among allthe tested schemes, the one using a layer of mask fabric laid every 20cm in the soil sample achievedthe highest reinforcement effect coefficient of 1.663. In the comparison tests of different mask contents, a mask content of 30 in the soil sample achieved the highest reinforcement effect coefficient of2.3. However, the data suggested that there was still potential for further improvement. The researchresults can serve as a reference for the improvement of coal gangue subgrade fillers.
LI Junpeng, ZHANG Chengcheng, SHI Bin, CHEN Zhuo, XIE Tao, GUO Junyi
2024(2):434-441, DOI: 10.13409/j.cnki.jdpme.20221204002
Abstract:
Using distributed acoustic sensing (DAS) technology in conjunction with underground telecommunicationfiber networks for dynamic urban security monitoring, including perimeter security (intrusion)monitoring, pipeline leakage detection, and traffic condition assessment, represents a new approach.This research aimed to investigate the influence of moisture content variations in geotechnicalmediums around unlit fibers on DAS amplitude response characteristics. To achieve this, the paper designedDAS amplitude response tests using sandy soils with varying moisture contents (0%, 5%,10%, 15%, and 20%) and two excitation modes: a small ball impacting a disc and directly on sandysurface. The test results revealed that: (1) Vibration signals generated by a free-falling ball impactingthe sandy surface, coupled with the setup of a ring sensing optic fiber, could enhance the DAS signalto-noise ratio, thereby increasing the reliability of the testing apparatus and the reproducibility of the results. (2) This study also identified a critical moisture content level that affected the DAS signal am plitude, which was caused by the combined effects of the sand's pseudo-cohesion and the attenuationof the acoustic wave propagation. Below this critical level, the DAS signal amplitude decreased withincreasing moisture content, whereas above it, the amplitude increased with higher moisture levels.(3) The contact method between the balls and the sand had a significant impact on DAS amplitude responsedue to the differences in sand's pseudo-cohesion and the energy conversion upon impact. Thefindings provide a theoretical basis for the application of DAS technology in precise monitoring of urbanunderground engineering safety.
JIN Dandan, SHI Zhan, WANG Binghui, ZHANG Lei
2024(2):442-449, DOI: 10.13409/j.cnki.jdpme.20221130004
Abstract:
This study aims to uncover the development modes of dynamic pore pressure in saturatednon-cohesive soil layers under impact loading and its variation due to soil layer conditions. Impact testswere conducted on layered saturated soil under different soil layer conditions using a self-developed impactload testing device, and the characteristics of dynamic pore pressure development and soil settlementwere analyzed. The results showed that under impact loading, the development of dynamic porepressure in soil underwent two distinct stages: a transient response stage and a steady-state response stage, with the latter characterized by a slow followed by a rapid decline. In single-layer soil, the dynamicpore pressure in saturated sand soil increased sharply after impact loading. With the increase ofparticle size, the peak pressure rose and the dissipation time shortened. In dual-layer soil, the steadystatedynamic pore pressure stage changed significantly due to permeability coefficient variations betweenthe upper and lower soil layers, markedly altering the reduction process in the lower soil layer.Presence of a relatively impermeable interlayer caused a noticeable plateau across all measuring pointsin the pressure reduction phase, significantly slowing the decrease rate, particularly in the soil abovethe impermeable layer compared to below it. With interlayers, experiments showed significant "waterfilm" formation with non-uniform distribution, reaching up to 2cm in thickness. At the same time,each impact load resulted in noticeable soil settlement, and the extent of settlement gradually diminishedwith subsequent impacts.
ZHOU Enquan, YAO Yuan, WANG Long, BU Chunyao, YI Sihang
2024(2):450-458, DOI: 10.13409/j.cnki.jdpme.20220724004
Abstract:
In order to study the liquefaction mechanism of saturated sand, a particle flow calculationmodel was developed to investigate its dynamic response under cyclic loading using isochoric loading.The study examined the dynamic response of saturated sand under different confining pressures andloading amplitudes, exploring the development characteristics of inter-particle force chains. Using thebasic relationships of Shannon entropy, Boltzmann entropy, and Clausius entropy, a method for calcu-lating particle entropy in saturated sand was established based on inter-particle force chains. The devel-opment characteristics of particle entropy in saturated sand were analyzed. The results showed that thetotal number of initial force chains in saturated sand was primarily influenced by confining pressure and increased with higher pressure. Under cyclic loading, the total number of force chains between saturat-ed sand particles gradually decreased, with strong force chains transitioning to medium and weak forcechains. The particle entropy of saturated sand exhibited a two-phase characteristic, initially increasingand then decreasing. Confining pressure and loading amplitude had no significant effect on the particleentropy peak value, which was 0.92 under different cases. The peak value of particle entropy was de-fined as the phase-change particle entropy. The saturated sand with phase-change particle entropyshowed mechanical characteristics at the solid-liquid critical state, indicating the transition of saturatedsand from a solid state to a cyclic liquefaction state.
SUN Shuai, CHANG Liancui, ZHANG Huang, DING Jianwen, LIU Jinyu
2024(2):459-466, DOI: 10.13409/j.cnki.jdpme.20221112004
Abstract:
This study investigated the response of existing buildings to the side-crossing of shield tunnelconstruction. It focused on shallow foundation buildings intersected by the shield tunnel along the north-ern extension of Nanjing Metro Line 1. Field data on building settlements were analyzed, and a numeri-cal model was established using PLAXIS 3D software. The study examined how different horizontaldistances between the tunnel and the building, as well as various crossing angles, affected the charac-teristics of differential settlement and twist deformation. The results showed that as the shield's excava-tion surface approached the building, the differential settlement and twist deformation of the buildinggradually increased. The differential settlement reached its maximum when the shield machine directlypassed underneath, after which it stabilized. The peak twist deformation occurred when the excavation surface reached the midpoint section of the building, and gradually decreased thereafter. When the ratioof the horizontal distance between the building's center and the tunnel's axis to the tunnel's outer diame-ter ranged from 0.5 to 2 (L/D=0.5~2), the differential settlement of the building was larger, andreached its peak when L/D ratio was 1.5. As the shield crossing angle increased from 0° to 90° , themaximum differential settlement of the building increased accordingly. In contrast, the final twist defor-mation increased first and then decreased, reaching its peak at 45° crossing angle. The research resultsprovide references for similar projects involving shield tunneling passing through shallow foundationbuildings.
CHEN Zhimin, LIU Baoli, LI Ning, LI Jiangpeng
2024(2):467-477, DOI: 10.13409/j.cnki.jdpme.20220928003
Abstract:
Moraine deposits, which are widely distributed in southeastern Tibet, pose significant risksto engineering projects. In order to study and improve their shear performance, well-graded similarmaterials replicating moraines were prepared using the principle of similarity. Under different freezethawcycles and moisture content conditions, direct shear tests were conducted on these similar materials.Triaxial tests were conducted with the addition of engine oil and fly ash admixtures to study theirimpact on the shear strength parameters of the moraine-like materials. The results showed that: (1) Indirect shear tests, with the increase of vertical pressure, the displacement-shear stress curve of moraineschanged from a weak strain softening type to a weak strain hardening type. (2) The influence ofmoisture content on moraines' shear strength was affected by the number of freeze-thaw cycles. (3) Afterfive freeze-thaw cycles, the material reached a threshold in shear strength. (4) Engine oil and flyash had opposite effects on the shear strength indices (cohesion and internal friction angle) of the moraines.
YANG Shaopeng, YANG Aiwu, LANG Ruiqing
2024(2):478-487, DOI: 10.13409/j.cnki.jdpme.20221124002
Abstract:
A new curing technique was used to treat blow-filled soils with high moisture content. Theinfluence of this technique on creep deformation and shear strength indices of cured lightweight blowfilledsoils was studied using triaxial rheometer, considering the number of wet-dry cycles, confiningpressure, and initial static deflection stress. The test results showed that the blow-filled cured light-weight soils featured the advantages of low density, light mass, and high strength. Increasing the con-fining pressure, to some extent, could effectively alleviate the creep deformation of the soil, whereasthe initial static deflection stress had less effect on it. The first seven wet-dry cycles had the greatest effect on the soil's damage stress, after which it remained basically stable. The shear strength indices, cand φ, decreased gradually with the increase in initial static deflection stress, and showed a pattern ofinitial decrease followed by a gradual stabilization with the increase of wet-dry cycle numbers. Both in-dices decreased exponentially over the first seven wet-dry cycles, and after that, the changes weresmaller and gradually formed stability. Based on the relationship curves between c, φ values, andtime, predictive equations for c and φ values of blow-filled cured lightweight soils under different de-flection stresses were constructed, respectively. By examining the development of creep curves and us-ing regression analysis with confining pressure, initial static deflection stress, and wet-dry cycle num-bers as variables, a predictive model for the creep deformation of blow-filled cured lightweight soilswas established, and its feasibility was verified. The results can provide a theoretical basis for practicalengineering applications.
2024(2):488-494, DOI: 10.13409/j.cnki.jdpme.20220704005
Abstract:
Construction of underground tunnels inevitably involves crossing liquefiable strata, which,under seismic activities, can lead to soil liquefaction and subsequent structural damage. Based on theTangwang Avenue River-Crossing Tunnel project in Bozhou, Anhui Province, the study employed indoorshake table experiments to design and analyze a scale model. It analyzed the vibration-induced liquefactionresponse patterns of the ground soil and tunnel structure, while investigating the buoyancydrivendeformation mechanism of the river-crossing tunnel during seismic liquefaction. The results indicatedthat the upper soil layer reached liquefaction approximately 1.5 seconds later than the lowerlayer, showcasing a more pronounced reduction in shear strength in the upper soil. As the soil depth increased,the rise in excess pore pressure accelerated and its peak was higher. At the start of vibration,the initial liquefaction in the lower soil layer led to a certain downward displacement. Subsequently, asthe buoyant force exceeded the effective bearing capacity, the tunnel gradually rose and stabilized. Afterthe cessation of vibration, the tunnel uplift displacement was 8.9 mm.
-
Experimental Study of a Tunnel-Group Metro Station in Rock Site under Strong Earthquakes
LI Ruozhou, HE Weiguo, YUAN Yong, LI Qingfei
Abstract:
Abstract:To investigate the dynamic characteristics of the tunnel-group metro station in rock site under earthquake, a large-scale shaking table test model of the structure with a scale of 1:30 was designed. The model was subjected to transverse inputs of peak accelerations of 0.07 g, 0.15 g, 0.21 g, 0.30 g, 0.50 g, 0.70 g, and 1.0 g, representing seven different intensities of artificial seismic waves.The study focused on the acceleration response characteristics, displacement response characteristics, structural damage modes, and dynamic strain response characteristics of the tunnel-group metro station under strong earthquakes. The results showed that the amplification factors curve of Arias Intensity reveals that the model rock and the hall lining structure entered into the plastic damage state after the peak acceleration of 0.5 g. The platform lining structure gradually entered into the damage state from the plastic state after the peak acceleration of 0.3 g, and the energy dissipation increases gradually. With the increase of earthquake intensity, the relative displacement of the hall cross-section increases significantly, and the gap between the peak relative displacements of the open section and the non-open section widens further. The cracks of the structure are mainly distributed in the longitudinal direction, and the longitudinal cracks in the middle of the straight wall of the platform are wide and long, while the middle of the straight wall of the hall did not produce obvious cracks. With the increase in seismic motion intensity, the main frequency of the structural transfer function gradually decreased, with the main frequencies being 22.7 Hz and 18.5 Hz in the elastic and plastic damage stages, respectively. The tensile strains at the same locations in the VL section (the lower section of the vertical connecting passage) are larger than those in the HR section (the right section that connects the horizontal connecting passage) under transverse excitations, and the maximum tensile strain occurs in the arch shoulder of the VL section.
- 1
-
Seismic response of offshore wind turbines based on monitoring data and quasi-static calculation
DU Peng, YANG Yang, CHENG Wei, LI Ming, XU Guangwei, SHEN Panpan
Abstract:
The harsh marine environment condition and frequent earthquake activities seriously threatens the safety of offshore wind turbines which are close to the seismic belt along the southeast coast and the seismic belt around the Pacific Ocean. Offshore geological conditions in China are complex, with deep and weak soil seabed, and a wide range of shallow cover layer geological areas, which leads to the unfriendly geological conditions. The seismic response of OWT earns more and more attention among engineers and researchers in the area. In this paper, based on one wind farm project in China, seismic response of offshore wind turbines (OWT) with monopile foundation utilizing monitoring data under earthquake excitation and quasi-static calculation results. Firstly, the data-driven random subspace method (data-SSI) is used to identify the frequency, damping and mode shape of the OWT. Then the acceleration response and spectrum characteristics of different measuring points are analyzed, and the time-frequency variation of each measuring point response is analyzed by wavelet transform method. Finally, the quasi-static calculation method is used to calculate the response of the tower and monopile foundation under the inertia force of the superstructure. The results show that the peak acceleration occurs at the middle part of the tower and the high order modes of the OWT are significant under earthquake action, and the time-frequency spectrum results show that the vibration of the fan is not dominated by the first-order mode under earthquake excitations, and frequency change at the top of the tower is very complicated. The horizontal deformation of the tower and the stress of the tower meet the requirements of the code. The analysis results can provide reference for researchers and designers in OWT field to evaluate the safety of OWT, and have great value in application.
- 1
-
Macroscopic hazard characteristics of the 2023 Gansu Jishishan Ms6.2 earthquake and some proposals
JIANG Wei, WANG Yong zhi, YUAN Xiaoming, TANG Zhaoguang, CHEN Longwei, NIE Guibo, LI Zhaoyan, ZHANG Haoyu, WANG Yunlong
Abstract:
On December 18， 2023， an earthquake of magnitude Ms6.2 occurred in Jishishan County， Gansu Province， which showed the characteristics of "same?seismic level and heavy disaster" and trig? gered special flowslide geologic hazards compared with previous earthquakes of the same magnitude. Through the on?site seismic damage investigation， visiting the affected people and collecting geologi? cal data and related literature， we focused on the background and breeding geological conditions of this earthquake， compared the distribution differences between instrumental intensity and macro?intensity， counted the typical seismic damage characteristics of different residential houses and their proportion， and investigated the main causes of casualties； we also surveyed the macro features of secondary flow? slide disasters， and raised some key questions about their causes and triggering conditions. A number of key questions were raised to reveal its causes and triggering conditions. The results show that there are obvious differences between the instrumental and macroscopic intensities， which are mainly due to the complex topographic and geological conditions， the differences in the economic development level of different towns and townships， the differences in the seismic?resistant capability of houses， and the lack of a consistent standard for the deployment of the intensity instrumentation； the surface accelera? tion recorded in the strong?seismic observation is obviously greater than that in the 2021 Yangbi Ms6.4 earthquake， and the area of Intensity Zones VI， VII， and VIII is 2.3， 1.5， 2.5 times that of the 2022 Lushan Ms6.1 earthquake， respectively. which is an important cause of the same magnitude earthquake causing severe damage； the flowslide buried and destroyed the houses， the walls of the kangtou?connected showers collapsed， and the earthquake occurred in the middle of the night are the main factors of the heavy casualties of this earthquake. The flowslide area is about 3 km long， with a difference in elevation of about 85m between the front and back， covering an area of about 390，000m2 and spreading out to a height of about 3m above the ground， with a number of isolated islands remain? ing in the collapse area， which may be triggered by a combination of external factors such as long?term irrigation of farmland， enrichment of the underground water ， and the direction of the seismic main vi? bration being the same as that of the flowslide movement and the natural valley direction， and the in? trinsic mechanisms such as wet subsidence of loess and liquefaction of the soil， and so on， and the spe? cific causes of the disaster， the physical mechanisms， and the triggering conditions need to be verified jointly by various means. The survey proved that building and reinforcing existing buildings in accor? dance with earthquake?resistant standards and strengthening rural residents' awareness of earthquake prevention and mitigation and their knowledge of emergency evacuation are effective measures to re? duce the casualties caused by earthquakes.
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
-
Fiber Optic Monitoring and Numerical Simulation of Loading and Deformation Behavior of Diaphragm Wall
LIU Tian-xiang, ZHU Hong-hu, CHENG Gang, TAN Dao-yuan, WEI Guang-qing, SHI Bin
Abstract:
As a common support method for deep excavation, diaphragm walls have complex loading and deformation regulation, which is a hot research topic in excavations. In this paper, based on the fiber Bragg grating sensing technology, the horizontal displacements of a diaphragm wall of a subway station was measured. The monitoring data was compared with the numerical simulation results, and the rationality of the numerical analysis model was verified. Based on the numerical analysis model, the variation law of the horizontal displacement of the underground diaphragm wall in the soft soil layer of different thickness was studied. The critical thickness ratio was calculated by the wall displacement gradient Dw and the soft soil displacement gradient Dr. The results show that the variation of horizontal displacement of diaphragm wall with the thickness of soft soil is generally "convex belly". The deformation of the diaphragm wall can be divided into relatively stable zone, linear growth zone, maximum deformation zone and linear decline zone along the depth direction. Using Dw and Dr to calibrate the critical thickness ratio as 0.24. The earth pressure changed steadily in the first four excavation processes but changed significantly in the fifth excavation process as well as 40 days after construction. The research results provide a valuable reference for the design, construction, and monitoring scheme of similar projects.
- 1
-
Inversion and Prediction Simulation Study of AruIce Avalanche-Debris Flow Motion Process
LI Yang, TANG Minggao, SHUAI Yiyao, ZHAO Huanle, LI Chaorui, NI Wentao, LI Guang
Abstract:
As one of the most disastrous geological disasters in the cryosphere, ice avalanche has the characteristics of complex movement process, high difficulty in prediction and serious disaster consequences. On July 17 and September 21, 2016, two giant ice avalanche-debris flow events occurred in Ali Prefecture, Tibet, which caused serious harm to the life and property safety of local residents and the ecological environment, so PFC3D was used to invert the two ice avalanche-debris flow motion processes, and on this basis, the potential ice avalanche-debris flow danger in the surrounding area were simulated and predicted. The results showed that: (1) the movement time of the two ice avalanche-debris flows was 300s and 240s, the peak average velocity of particles was 32.05m/s and 34.80m/s, respectively, and the volume of the first ice avalanche into the lake was about 8.47×106m3. (2) The energy transfer at the front and rear is the key mechanism for high-speed long-range movement of ice avalanche-debris flow; (3) It is predicted that the area of the main accumulation area on the northwest side is about 1.1km2, the area of the small accumulation area on the northeast side is about 0.3km2, and the total area of the danger area is 3.28km2 after the ice avalanche of the Aru 85 glacier(hidden danger of ice avalanche), which has certain scientific value and practical significance for the ice avalanche disaster prevention and mitigation work on the Qinghai-Tibet Plateau.
- 1
-
Research on the Factors Influencing the Uniformity of Air Curtain and Its Dust Separation Effect
WANGPei, JIANGZhongan, WANGHui
Abstract:
Recently, air curtains, as a device to effectively isolate easily diffused dust, have been frequently used in mining and tunneling construction process where more dust is produced, while a uniform air curtain will bring better dust isolation effect. Fluent numerical simulation combined with similar experimental methods were used to analyze the effect of changes in the diameter of the air curtain and the air duct structure inside the air curtain on the uniformity of the air curtain, and the air curtain designed to supply air uniformly was installed in the actual construction of the tunnel model to simulate and analyze the effect of its dust insulation.Results show that: the diameter increases, the airflow axial inertia force inside the air supply device decreases, which gives sufficient time to change the outflow direction. Meanwhile, the axial static pressure of the air curtain device is more uniform to form a more homogeneous air curtain. However, the influence of the diameter change on the homogeneity of the air curtain is not linear, i.e., there exists a critical diameter, which makes the improvement of the homogeneity of the diameter continue to increase insignificantly, and the range of the diameter of the air curtain increases with the increase of the length of the air supply device.On the basis of the air curtain device with a length of 1m and a critical diameter of 180mm, after installing the wedge-shaped fan-shaped blocking body with a calculated arc height of 149.9mm according to the principle of air duct design, the average pressure gradient inside the air curtain device was reduced from 38.4Pa/m to 19.3Pa/m, and the uniformity of the outlet wind speed was increased from 87.6% to 93.2%, and the uniformity of the air curtain was significantly improved;Finally, after installing the air curtain, the rebound dusty airflow in the dust isolation area was blocked, and the airflow in the area became chaotic and complex with increased vortex, and the dust retention time was increased to allow a longer time for the relatively large dust particles to settle. The dust concentration in the whole dust isolation area increased significantly, and the effect of air curtain dust isolation is remarkable.
- 1
-
Seismic behavior of masonry wall strengthening with ultra-high ductility concrete
U Xiaoxin, XIE Qun, ZHAO Peng, JING Yuwei, LIN Mingqiang
Abstract:
In order to study the seismic performance of masonry wall strengthened with Ultra-high Ductility Concrete (UHDC), cyclic experiment of two solid walls and two hollow walls had been carried out on. Compared with unreinforced wall, the strength of solid wall increased by 31% while peak displacement reduced by 30%. For hollow wall, the strength increased by 223%, and peak displacement dropped by 471%. OpenSees software was adopted to model UHDC reinforced masonry walls, and the influence of key parameters on seismic behavior, such as UHDC layer thickness, reinforcement mode and compressive stress, had been analyzed respectively. The results showed that the peak strength for UHDC solid wall increased by 16.0%, 36.2% and 56.1% respectively, when the UHDC layer thickness was 10mm, 20mm and 30mm respectively, however the peak displacement reduced by 28.3%, 26.7% and 26.7%, respectively. For hollow wall, the peak strength increased by 117.4%, 179.5% and 243.4% respectively, and peak displacement increased by 345.5%, 522.7% and 506.1% when the UHDC layer thickness is 10mm, 15mm and 20mm respectively. When the vertical compressive stress is 0.6MPa and 0.9MPa, the peak strength capacity of solid wall increased by 16.8% and 33.0% respectively over 0.3MPa, and the peak displacement reduced by 12.0% and 16.0% respectively; the peak strength of hollow wall increased by 6.5% and 10.5% over 0.15MPa, and the peak displacement increased by 2.8% and 0.0% respectively. When using whole surface reinforcement, oblique strip reinforcement and orthogonal strip reinforcement, the peak strength of solid wall increased by 36.2%, 12.0% and 5.4% respectively, however the peak displacement reduced by 26.7%, 28.3% and 28.3% respectively; the peak strength of hollow wall increased by 179.5%, 80.1% and 39.3% respectively, and the peak displacement increased by 522.7%, 203.0% and 203.0% respectively. Finally, the calculation formula of the shear bearing capacity of UHDC reinforced masonry wall is proposed. Compared with the test and simulation results, the theoretical value has good accuracy, which can provide theoretical support for the reinforcement design.
- 1
-
Effect of Variability of Soil Dynamic Parameters on Ground Motion Parameters for Deep Soft Sites
CHEN Guo-xing, LIU Xue-zhu, WANG Bing-hui
Abstract:
- 1
-
LIU Hanlong, REN Huiqi, CHEN Jun, ZHANG Wengang, LI Zhe, YIN Yueping, ZHANG Qin, WANG Luqi
2023,43(5):917-922, DOI: 10.13409/j.cnki.jdpme.20230921004
Abstract:
In the context of global climate change and increasingly active geological activities， China urgently needs to achieve rapid and efficient emergency response to natural disasters， and the corresponding upgrading of disaster prevention and control industries is also imperative. This study employs a comprehensive research methodology， encompassing literature review， on-site research， expert consultation， and questionnaire survey. Furthermore， combined with the development objectives of key steps within natural hazard mitigation， the issues and challenges faced by the natural disaster prevention and control industry were analyzed to propose the development paths of technology breakthroughs. On this basis， the following strategies were summarized. A more comprehensive standardization system should be established to seriously verify professional qualifications， control the market dynamics of industries in real-time， and ensure efficient competition in the industrial market. Leveraging advantages of localized development， the development of natural hazard prevention and control industries should be clustered to connect multiple chains. Led by the basic research on natural hazard prevention and reduction， the upgrading of natural hazard industries should be completed through theoretical innovation and technological iteration. Moreover， the industry should highlight the overall， systematic， and synergistic characteristics to enhance international competitiveness within disaster prevention and reduction. This paper aims to provide forward-looking， targeted， and evidence-based scientific references to facilitate the high-quality and expeditious development of the natural disaster prevention and control industry.
-
ZHANG Lei, SHI Bin, WEI Guangqing
2020(5):698-705, DOI: 10.13409/j.cnki.jdpme.2020.05.003
Abstract:
Among other factors,artificial slope cutting is one of the most common triggering factors oflandslide. In this paper,a series of model tests and numerical simulation have been conducted to investigate the failure mechanism and evolution process of the slope under slope cutting. As the coupling between sensing cables and soil directly affects the accuracy of monitoring results. Firstly,a new pullout apparatus is designed and the coupling deformation relationship between sensing cables and soil isacquired through pull-out tests under different confining pressures. According to the pull-out tests,asurcharge loading test model was designed. Strain-sensing cables that can capture the strains at different positions of the model slope were embedded in the soil mass. The measurement data of the cutslope were analyzed. It can be found that an abnormal strain-field area obtained by horizontal and vertical sensors coordinated with the location of the potential slip surface. This is verified by a comparisonbetween the measurements of the cables and numerical simulation results. Based on the BOTDA data,an empirical relationship is explored between the horizontal characteristic maximum strain and thesafety factor to estimate the slope stability condition and perform early-warning of landslide under theaction of slope cutting. The conclusions drawn in this study are of great significance to stability evaluation of artificial cut slopes.
-
ZHOU Yun, CHEN Zhangyan, GUO Yangzhao, ZHANG Chao
2021(4):753-767, DOI: 10.13409/j.cnki.jdpme.2021.04.005
Abstract:
In order to improve the seismic performance of conventional infilled masonry wall，an innovative configuration named damped infilled wall/wallboard(DIW)was proposed by introducing the principle of viscoelastic damper. DIW has a simple construction，explicit working mechanism and independent intellectual property right. In this paper，the configuration and working mechanism of DIW was introduced. The material suitable for damping layer construction and its corresponding hysteretic performance were given. Seismic performance tests were carried out on DIW unit as well as plane frame structures with DIW. The in-plane working mechanism that the shear hysteretic deformation which is casued by relative movement between adjacent subpanel of DIW dissipates the input seismic energy was revealed. The double bracing macro-modelling method was proposed. The proposed model was used in the time-history analysis of a 3D frame structure with DIW. Results show that DIW is able to significantly reduce the influence on the dynamic characteristic and seismic performance of the main structures，and to protect the wall from suffering damages through decreasing the stiffness effect of wall/wallboard on structure. Out-of-plane performance of DIW was also studied by tests. The results reveal that the out-of-plane mechanism is the arching mechanism and the failure mode is fourhinge arching.The problems and directions that need to be further studied were given.
-
ZHEN Yiwei, LIU Shuguang, ZHONG Guihui, ZHOU Zhengzheng, FANG Qi, ZHENG Weiqiang, LIANG Jiyu
2022(1):1-11,23, DOI: 10.13409/j.cnki.jdpme.20210416004
Abstract:
Due to the strong surface disturbance caused by the "5.12" Wenchuan earthquake，mountain torrent disasters have occurred frequently in Wenchuan County in recent years，causing serious damage to local houses. In Wenchuan County，two mountain torrent disasters，"8.20" and "8.17"，occurred in 2019 and 2020. Taking some of the damaged village buildings in the two disasters as research objects，this paper summarized the damage characteristics of different structural types of buildings，the spatial variability of the damage degree of buildings along the river and the building masking effect，as well as the damage modes of impact，scouring，siltation and immersion through disaster data mining and typical case analysis. Based on the research and analysis，this paper improved the existing building damage grading criteria by combining the characteristics of mountain torrent damage，and then proposed the classification of mountain torrent damage to rural buildings. Applying random forest algorithm and statistical analysis methods，the main influencing factors of building flood damage and their relationships were comprehensively analyzed in terms of water depth exposure，site exposure，and physical vulnerability. Finally，based on the analysis of building damage，some suggestions were proposed to improve the flood mitigation capacity of buildings in mountainous villages. The research results lay the foundation for further research on the physical mechanism of building flood damage，and also provide references for flood prevention planning and disaster mitigation design of buildings in mountainous villages and towns.
-
YANG Dongxu, YOU Yong, WANG Junchao, YANG Dong, LIU Jiankang
2020(6):841-851, DOI: 10.13409/j.cnki.jdpme.2020.06.001
Abstract:
The southeast region of Tibet is the largest marine glacier area in China. For investigating the physical and mechanical characteristics of glacial tills along the Sichuan-Tibet railway， and evaluating their stability as a geological hazard source and engineering foundation， 32 points of glacial tills in the Parlung Zangbo basin were taken as cases. A series of in-site and indoor tests on natural density， grain size analysis， large direct shear， triaxial shear， compressive strength， permeability coefficient and so on were carried out. Combining with field investigation methods such as sectional surveying and mapping， the distribution， morphological characteristics， physical and mechanical properties of glacial till and their correlation were analyzed. The result shows that physical and mechanical properties are closely related to moisture content， void ratio and clay content. The natural density and compression modulus are negatively linear related to the void ratio. The vertical permeability coefficient and the free expansion ratio show a quadratic relationship with clay content. The shear strength and compressive strength are binary relationship with void ratio and moisture content. Start-up patterns in three different deposit sites (modern glacier tongue， middle reaches of the valley， and the main river bank) were summarized， and the stability of the glacial tills was preliminarily discussed. The countermeasures for dealing with the glacial tills in Sichuan-Tibet railway and highway projects were suggested， such as passing by bridges or tunnels， engineering slope， and cutting or foundation， etc.
-
YU Feng, ZHANG Chenrong, HUANG Maosong
2020(4):623-632, DOI: 10.13409/j.cnki.jdpme.2020.04.017
Abstract:
The monopile for offshore wind turbine sustains long-term cyclic load due to environment and scouring in the seabed. The long-term cyclic loading behavior of the pile foundation under scouring is an important problem in the design of monopile for an offshore wind turbine. Laboratory model tests were conducted to investigate the performance of a large diameter pile and a small diameter pile in sand subjected to scouring and long term lateral cyclic loadings, in which the influence of scour depth and cyclic loading amplitude on the long-term behavior of the two foundations was discussed. The test results show that the applied cyclic loading improves the post-cyclic capacity of single pile, especially for the small diameter pile. Scour leads to the reduction of post-cyclic capacity of single pile, the effect of which increases with the scour depth. Comparing with the large diameter pile, the increment of residual cumulative deformation of the small diameter pile is smaller in early cyclic loading stage. When the cycle number is larger than 1000 and the scouring depth is twice of the pile diameter, the development of the cumulative deformation of the small diameter pile approaches to be stable, while a further development of deformation appears in the large diameter pile. By bringing the scour affected capacity into the dimensionless cyclic loading amplitude parameters, the lateral cyclic cumulative displacement calculation model of the two kinds of piles under scouring is established, which is applicable to the prediction of long-term lateral cyclic cumulative deformation of single pile considering scouring.
-
CHEN Dawei, WU Zhijian, LIANG Chao, ZHOU Hanxu
2022(1):24-33, DOI: 10.13409/j.cnki.jdpme.20201024001
Abstract:
On September 14，2019，a large loess landslide occurred in Tongwei County，Dingxi City， Gansu Province. Through on-site investigation of the loess landslide and drone aerial survey，the topography，geomorphology，hydrogeology and other conditions that gave birth to the landslide were ascertained，and the morphological characteristics，structural characteristics and movement patterns of the landslide body were studied in-depth，revealing the Tongwei landslide Disaster mechanism. The high-density electrical method is used to detect the stratum structure，thickness of the sliding body， groundwater distribution and spatial distribution of the landslide area. Combining the finite element method and Morgenstem-Price method to calculate the stability of the slope，the distribution of the maximum shear strain and the variation of slope stability with rainfall duration are obtained. The results show that：(1)the shape of the Tongwei landslide is a chair-like shape，which is divided into three typical failure areas，forming a large number of vertical ridges，and the thickness of the loess sliding is approximately 8~50 m；(2)the Tongwei landslide belongs to the "traction-push" type of bedding landslide，and the movement mode is "pull toe instability traction-hindered sliding in the middle partinstability shift in the rear part"；(3)the groundwater is mostly fissure karst water，and the geological structure is not obvious. The geological structure activities such as early earthquakes have a great influence on the stratum；(4)the stability of loess slope decreases continuously with rainfall duration，and the maximum shear strain region is mainly distributed in the middle and upper part of the slope，and develops from mudstone contact to slope surface；(5)rainfall is the most direct factor triggering the Tongwei landslide，and the development of gullies，river erosion and agricultural production activities are important disaster-generating conditions
-
JIANG Haolin, ZHENG Jiangrong, HE Bin, BAO Haiying, DAI Xianpeng, SHAN Han, WANG Dawei
2021(4):909-916, DOI: 10.13409/j.cnki.jdpme.202107015
Abstract:
Jiangsu earthquake monitoring began with the establishment of Nanjing Beijige Seismic Station in 1930. Through the unremitting efforts，exploration and innovation of several generations of seismic workers，the ability and technical level of earthquake monitoring have made a great progress. Looking back on the development of Jiangsu earthquake monitoring system，we can find that it has developed from the operation of weicher seismograph in June 1932 into a multidisciplinary observation network covering the whole province including seismometry，geomagnetism，geoelectricity，deformation and fluid. Seismic monitoring has gone through a process from introducing foreign seismic instruments to completely independent research and development of devices，from analog observation to digital network observation，from manual waveform recognition to AI automatic recognition of seismic events. With the rapid development of science and technology in recent years，the continuous development of observation technology，and the innovation and updating of seismic observation equipments， rich seismic monitoring results have been achieved from the seismic observation network，precursor network and mobile monitoring network covering the whole province. A large number of obtained observation data have been widely used in earthquake quick report，earthquake prediction research， earthquake disaster prevention，earthquake emergency rescue and earthquake scientific research. It has provided a solid earthquake safety guarantee for the rapid economic and social development of Jiangsu. Things present are judged by things past.This paper reviews the development process of earthquake monitoring in Jiangsu，pays tribute to the efforts of the older generation of scientists. The development of earthquake monitoring science and technology is passing down from generation to generation， serving the high-quality development of the whole province，and writing a new development history of earthquake monitoring in Jiangsu.
-
WU Peisong, WANG Jian, OU Jinping
2020(3):317-325, DOI: 10.13409/j.cnki.jdpme.2020.03.001
Abstract:
Superstructures of seismically isolated structure keep in elastic or slightly elastic-plastic range subjected to rare earthquakes, thereby protecting superstructure effectively. However, very-rare earthquakes may happen in design reference period due to uncertainty of earthquake intensity and character. On basis of “survive rare earthquakes by sustaining significant damage but without globally collapsing” design, horizontal deformation of isolation bearings and overturning resistance under very-rare earthquakes, performance and cost of seismically isolated structure based on “survive very-rare earthquakes” are worth researching. Dynamic responses of three seismically isolated structures with different heights are obtained from elastic-plastic time history analysis. Main failure modes of seismically isolated structures subjected to very-rare earthquakes are presented by comparing the responses such as inter-story drift ratios, horizontal displacements of isolation bearings and overturning moments. The results show that under very-rare earthquakes, horizontal displacements of isolation bearing in all three classic seismically isolated structures are excessive, while other two responses both meet the requirements. With isolation bearings increasing suitably, new structures can avoid destruction by deformation of isolation layer increasing and survive very-rare earthquakes, while isolation effectiveness reduce slightly. Reducing the aspect ratio of superstructure appropriately can control the overturning of whole structure especially high-rise structure subjected to very- rare earthquakes. Therefore, considering both safety and economy, it is an effective and economical way to increase the ultimate displacement of isolation bearing, appropriately reduce the aspect ratio of high-rise seismically isolated structures, and realize resistance ability of isolated buildings subjected to very-rare earthquake.
-
ZHUO Weidong, WANG Zhijian, LIAO Liyun, CAI Zhehan, WANG Hongda
2020(4):483-489, DOI: 10.13409/j.cnki.jdpme.2020.04.001
Abstract:
To improve the seismic performances of bridges with very tall piers in high seismicity area, design concept of the bridge with very tall piers, which is composed mainly of concrete-filled steel tubular (CFST) columns and energy dissipating mild steel plates (EDMSP), is proposed based on the principle of earthquake restorable structures. Trial design of a bridge with the proposed innovative composite box section tall piers is carried out based on a typical continuous rigid frame highway bridge with tall RC box section piers. The static and seismic performances of the bridge according to fundamental loading combination and E2 level seismic action are analyzed respectively. The seismic performance of the designed bridge under E2 level seismic action is compared with the bridge with conventional RC box section piers. The results show that: (a) under fundamental loading combination, the bridge with innovative composite box section piers can well meet the requirements of structural strength and stability; (b) under E2 level seismic action, the conventional designed bridge experiences medium damage in the piers, while only the replaceable EDMSP elements of the innovative designed bridge undergo plastic deformation, indicating the innovative designed bridge is earthquake restorable; (c) the seismic displacement responses of the innovative designed bridge is significantly smaller than that of the conventional designed bridge under E2 level seismic action.
-
LIU Guoyang, LI Junjie, KANG Fei
2020(5):679-689, DOI: 10.13409/j.cnki.jdpme.2020.05.001
Abstract:
A three-dimensional discontinuous deformation analysis(3D DDA)method was used tooutput the kinetic energy and motion trajectory of rolling blocks. Compared with the results of the existing laboratory experiment and numerical simulation method,the accuracy of the 3D DDA methodwas verified. By analyzing the influence of the rockfall platform on the kinetic energy,motion trajectory and movement law of blocks along rock slopes with different slope heights,slope angles and foldingpoint positions,the influence law of the rockfall platform on the block movement was studied. Finally,the rockfall slope with a complex slope shape at Lang village in Tibet was simulated,and the protective effect of the rockfall platform on rockfall disaster was analyzed. The results show that the rockfall platform can decrease the kinetic energy of the rolling block,change the block motion trajectory,and reduce the impact of the rolling block on the protection structure or the traffic line at the slope bottom. Meanwhile,the general laws including the block movement and the corresponding platform design width under different slope characteristics are given,and they provide a basis for the design ofrockfall platform.
-
SHAO Junhu, ZHAN Yulin, CHEN Ning, XIANG Zhengsong
2022(1):81-91, DOI: 10.13409/j.cnki.jdpme.202003018
Abstract:
Regarding frequent accidents of ship-bridge collisions around the world，a finite element model of barge-pier collision was established to study the dynamic response and damage characteristics of the pier under barge impact. The reliability of the finite element model is verified by comparing it with the results of the previous drop impact test. Based on the finite element model，the dynamic response and damage evolution mechanism of piers under 1000 t barge collision at the speed of 4 m/s are investigated，and the influence of impact velocity，impact tonnage，impact point and axial compression ratio on the damage characteristics is studied. The results show that the most disadvantageous positions is the pier bottom and collision point area；the yield strength of rebar is improvedby 11.7%~ 22% due to the strain rate effect，which increases the resistance of the pier；the collision velocity and tonnage can affect the damage degree of the pier，but do not affect the damage characteristics of the pier； the damage degree and characteristics are changed by the impact point and the axial compression ratio； the resistance of piers increase with decreased impact points and increased axial compression ratio.
-
LI Yang, XU Chengshun, DU Xiuli
2020(3):326-336, DOI: 10.13409/j.cnki.jdpme.2020.03.002
Abstract:
During the Kobe earthquake in Japan, different degrees of earthquake damage occurred on the subway underground structures. Only one zone of the standard section of Daikai station totally collapsed, while the other zones of Daikai station, its running tunnels and other subway underground structures did not have serious earthquake damage. In this paper, the earthquake damage responses of the standard section, central hall and running tunnel structure of Daikai station were analyzed based on nonlinear finite element analyses which can reasonably simulate the damage of underground structures. Numerical results indicate that different width of structural cross section and burial depth lead to different overlying earth pressure on the structures at the standard section, central hall section and running tunnel section. The different overlying earth pressure generated different axial compression ratio of the three structural columns. In addition, the three structures with different lateral racking stiffness had different degree of damage and stiffness degradation, and further led to different lateral racking deformation. Eventually, the columns of Daikai station standard section destroyed due to the excessive relative deformation under the high axial compression ratio, which caused the total collapse damage to the entire frame structure. On the contrary, the columns of central hall and running tunnel section have not destroyed because there were not excessive relative deformation under the lower axial compression ratio, which kept the bearing capacity of the entire frame structure.
-
LIU Xuening, CHEN Guoxing, REN Wei, JIN Dandan, XU Hangang
2020(4):498-508, DOI: 10.13409/j.cnki.jdpme.2020.04.003
Abstract:
The nonlinearity of soil has a great influence on the spectral characteristics and intensity of ground motions. The modified Matasovic model is accepted to well characterize the nonlinear behavior of soil. The profile soil models of 50 boreholes for the quaternary deep sediment layers are established for site seismic response based on software DeepSoil. The predominant period Tp, average spectral period Tavg of the acceleration response spectrum and the mean period Tm of the Fourier amplitude spectrum of an acceleration time history are employed as the proxy to characterize the spectral characteristics of surface ground motions. The ground motion intensity is characterized by the Arias strength Ia and the peak ground acceleration (PGA). The results show that: (1) Tp doesn't characterize the changes of seismic motions spectral characteristics during the seismic wave propagating from bedrock to surface ground. Tavg and Tm have a good similarity in characterizing the spectral characteristics of seismic motions. (2) When the seismic bedrock motions are rich for high frequency components, Tavg and Tm show a linear growth trend with increasing peak bedrock acceleration. However, there are inflection points in the growth trend lines of Tavg and Tm if the seismic bedrock motions are rich in low frequency components. (3) The nonlinear generation rates of PGAs and Ia with increasing peak bedrock acceleration are essentially consistent, and the values of PGAs and Ia show much greater dispersion with increasing peak bedrock accelerations.
-
2022(1):224-230, DOI: 10.13409/j.cnki.jdpme.201909030
Abstract:
At present，the dynamic analysis of slope mainly focuses on soil slope or rock slope，but ignores soil-rock mixture slope which is a special geomaterial slope. However，few studies have simplified the soil-rock mixture slope into equivalent homogeneous soil slope，ignoring the existence of block rock. By using digital image processing technology，a meso-structure model of an actual soilrock mixture slope is established，and the deformation and stability of equivalent homogeneous soil slope and soil-mixture slope under seismic load are analyzed and compared by using the dynamic analysis module of FLAC3D software. The following conclusions are drawn：the soil-rock mixture slope first appears shear failure at the foot of the slope under earthquake；then gradually develops tensile failure at the top with the increase of action time；finally forms a complete failure zone. The sliding surface of the soil-rock mixture slope is restricted by the position of the rock and has the phenomenon called stone-winding phenomenon. Under the same seismic load，the failure zone of soil-rock mixture slope is slower than that of the equivalent soil slope，and the final permanent displacement is smaller than that of the equivalent soil slope. The existence of block stones increases the shear strength and stability of soil-rock mixture slope.
-
WANG Xiao, CHEN Hui, WANG Zhaoming, ZHANG Dong, ZHAO Wei
2020(3):460-466, DOI: 10.13409/j.cnki.jdpme.2020.03.019
Abstract:
The finite element inversion analysis method, allowing for describing the creep behavior of soft soil, is presented for simulating the subgrade settlement. The finite element analysis software, ABAQUS, was embedded into the improved whale algorithm by MATLAB, thus the calculation parameters of soft soil can be obtained quickly and accurately. The modified Drucker-Prager and time hardening creep model were used to simulate the subgrade settlement and deformation. In order to test the reliability of the proposed method, the finite element inversion model was built for a highway subgrade crossing soft soil and the deformation of the subgrade was simulated during the whole construction period. The simulation results indicate that the subgrade deformation obtained by the inversion analysis agreed well with the measured data. In addition, the post-construction settlement was also predicted and the settlement was within 10 cm in ten years after construction, which provides good theoretical guidance for the operation and management of the highway.
-
CHEN Guoxing, YANG Wenbao, YUE Wenze, QIN You
2020(1):1-8, DOI: 10.13409/j.cnki.jdpme.2020.01.001
Abstract:
In order to explore the characteristics of dynamic shear modulus G and damping ratio λ for various marine soils in the Jintang Strait, a series of resonant column tests were carried out on various undisturbed marine soils with different depth from four sampling boreholes in the Jintang Strait. The test results show that: (1) various marine soils exhibit strong nonlinearity and hysteresis characterized by “low shear modulus and high damping ratio”; the maximum dynamic shear modulus Gmax for various marine soils increases with increasing depth, and the increasing rate of Gmax with soil depth decreases follwing the sequence of silty clay, silt, silty clay mixed silty sand and silty sand. (2) with increasing depth, the G/Gmax — γ curves of various marine soils shift towards the upper right characterized by low nonlinearity, while the λ — γ curves move downward and rightward characterized by decreasing hysteresis. (3) parameters of G/Gmax — γ and λ — γ curves of various marine soils with depth in the Jintang Strait are presented.
-
CHEN Guoxing, WU Qi, SUN Suyu, ZHAO Kai, Charng Hsein JUANG
2021(4):677-709, DOI: 10.13409/j.cnki.jdpme.2021.04.001
Abstract:
Earthquake-induced soil liquefaction is one of the leading causes of significant earthquake damage worldwide. It is also a complicated phenomenon of long-standing interest in the geotechnical earthquake engineering community. Assessment of soil liquefaction potential is an essential task in engineering practice. This paper provides an overview of the development and evolution of the procedures for evaluating soil liquefaction triggering during the last five decades. The focus here is on the more recent advances in the simplified procedures for soil liquefaction potential evaluation from both deterministic and probabilistic analysis perspectives. Over the past two decades，these simplified procedures have been advanced，especially in two aspects：(1)advance in both quantity and quality of the databases of case histories，in which sites were characterized by one or more in situ tests(such as the standard penetration test，the cone penetration test，the shear-wave velocity measurement，and the dynamic cone penetration test)，and(2)recognition of various uncertainties and development of probabilistic evaluation procedures. Insights are provided herein through a critical review of these advances. Discussions are also extended to a few correction factors that relate to the cyclic stress ratio and the cyclic resistance ratio in situ tests under a set of reference conditions. Cross-comparisons are made among selected representative methods of liquefaction potential evaluation，and issues encountered in these evaluations are discussed. Lessons learned from decades of research，development，and practice of soil liquefaction potential evaluations，as summarized in this retrospective review，offer a prospect for next-generation liquefaction triggering evaluation procedures.
-
XIAO Shihao, ZHANG Jie, GE Yixun, KONG Ming
2020(4):490-497, DOI: 10.13409/j.cnki.jdpme.2020.04.002
Abstract:
Soil liquefaction is a common natural disaster during earthquakes. In recent years, the evaluation of soil liquefaction potential based on shear wave velocity has received increasing attention. In this paper, the maximum likelihood method is used to calibrate the worldwide used deterministic liquefaction evaluation model based on shear wave velocity proposed by Andrus and Stokoe. On this basis, a probabilistic evaluation model of soil liquefaction potential based on shear wave velocity is proposed. The results show that the liquefaction evaluation curves obtained from lognormal distribution, normal distribution, minimum Gumbel distribution and maximum Gumbel distribution have some differences when the liquefaction probability is 5% and 15%, and little difference when the liquefaction probability is 35%. The model correction coefficient calibrated by the minimum Gumbel model is mostly supported by the liquefaction case database according to the Bayesian information criterion. The mean value of the model correction coefficient is 0.879, indicating that the factor of safety obtained by the model proposed by Andrus and Stokoe is smaller than the true factor of safety in the average sense. The coefficient of variation is 0.387, indicating that the model error involves some uncertainties. The liquefaction evaluation curve of the probability model established in this paper is consistent with that obtained by Bayesian mapping function in the literature, and is quite different from that obtained based on logistic regression method in the high cyclic stress ratio range in the literature.
-
HUANG Cheng, CHEN Ningsheng, ZHANG Youyi, ZHANG Yong
2020(5):690-697, DOI: 10.13409/j.cnki.jdpme.2020.05.002
Abstract:
A large number of soil slope collapses-slides disaster have developed after the“8.8”earthquake in Jiuzhaigou,which is more fragmented and has a smaller thickness. When the traditional transfer coefficient calculation model is applied to stability calculation of such slopes,there is a problemthat the overall slope calculation cannot reflect the stability of a slider. In this paper,the fragmenteddegree of collapse-slide slope is divided into:extreme fragmentation,high fragmentation,moderatefragmentation,slight fragmentation,and no fragmentation. Based on the transfer coefficient methodand considering the five degrees of fragmentation of the slope,this paper improves landslide stabilitycoefficient and thrust calculation model. Taking the collapses and slides of old Rexi stockade PowerPlant in Jiuzhaigou County as an example,the results of two calculation methods are compared. Theresults indicate:Compared with the traditional calculation method,the block differential stability calculation model more consistent with the actual situation,so there is a difference in the stability of eachslider calculated by this method. Some are not stable under extreme conditions and some are unstable.Based on the difference calculation results of the block method,a block control model for the collapseslide slope was obtained.
Volume ,2024 Issue 2
Prospect Forum
重大灾害“机理、监控和风险研究”专栏
Special Section on "The Mechanism,Monitoring and Risk Study of Major Disasters"
Mechanism, Monitoring and Risk Study of Major Projects
Special Section on "The Mechanism,Monitoring and Risk Study of Major Disasters"
重大灾害“机理、监控和风险研究”专栏
Research Article
Research Article
重大灾害“机理、监控和风险研究”专栏
Volume ,2024 Issue 2
Research Article
Bimonthly, founded in 1981
Editor-in-Chief：OU Jinping
Sponsor：China Association for Disaster Prevention; Jiangsu Earthquake Agency
Publisher：Editorial Office of Journal of Disaster Prevention and Mitigation Engineering
ISSN 1672-2132
