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Generalized response displacement methods for seismic analysis of underground structures with complex cross section

Earthquake engineering and engineering Vibration 2023年第4期22卷 979-993页

作者： Xu Zigang Ding Linling Du Xiuli Xu Chengshun Zhuang Haiyang Jiangxi Key Laboratory of Infrastructure Safety Control in Geotechnical Engineering East China Jiaotong UniversityNanchang 330013China Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education Beijing University of TechnologyBeijing 100124China

The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing geotechnical works(ISO 23469)and code for seismic design of urban rail transit structures(GB 50909-2014).However,there are some obvious limitations in the application of *** and the shear stress of the soil could be approximately evaluated for the structures having a simple cross section,such as rectangular and circular *** is necessary to propose simplified seismic analysis methods for structures with complex cross *** paper refers to the idea of RDM and proposes three generalized response displacement methods(GRDM).In GRDM1,a part of the soil surrounding a structure is selected to generate a generalized underground structure with a rectangular cross section,and the same analysis model as RDM is applied to analyze the responses of the *** GRDM2,a hollow soil model without a generalized structure is used to compute the equivalent load caused by the relative displacement of the soil,and the soil-structure interaction model is applied to calculate the responses of the *** GRDM3,a continuous soil model is applied to compute the equivalent load caused by the relative displacement and shear stress of the soil,and the soil-structure interaction model is applied to analyze the responses of the structure,which is the same as the model used in *** time-history analysis method(THAM)is used to evaluate the accuracy of the proposed simplified *** show that the error of GRDM1 is about 20%,while the error is only 5%for GRDM2 and *** the three proposed methods,GRDM3 has obvious advantages regarding calculation efficiency and ***,it is recommended to use GRDM3 for the seismic response analysis of underground structures that have conventional simple or complex cross sections.

关键词： underground structures seismic analysis response displacement method equivalent seismic load complex cross section

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Acoustic emission characteristics of damage evolution of multi-scale fiber reinforced rubberized concrete under uniaxial compression and tension after being subjected to high temperatures

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Frontiers of Structural and Civil engineering 2024年第8期18卷 1237-1266页

作者： Shaoqi ZHANG Yao ZHANG Qianru LEI Yumeng YANG Yichao WANG Fei XU Zhiguo YAN Hehua ZHU Laboratory of Fire Safety School of Safety Engineering and Emergency ManagementShijiazhuang Tiedao UniversityShijiazhuang 050043China Structural Health Monitoring and Control Key Laboratory of Hebei Province Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

Recently developed multi-scale fiber(i.e.,CaCO3 whisker,polyvinyl alcohol(PVA)fiber,and steel fiber)reinforced rubberized concrete exhibits excellent mechanical properties and spalling resistance at high *** of macro properties such as strength and Young’s modulus cannot reveal and characterize damage mechanisms,particularly those relating to the multi-scale fiber strengthening *** this study,acoustic emission(AE)technology is applied to investigate the impact of multi-scale fiber on the damage evolution of rubberized concrete exposed to high temperatures,under the uniaxial compression and tension loading *** mechanical properties,AE event location,peak frequency,b-value,the ratio of rise time to amplitude(RA),average frequency(AF)values,and AE energy of specimens are *** results show that the number of events observed using AE gradually increases as the loading *** crumb rubber and fibers inhibit the generation and development of the *** is concluded that both the peak frequency and b-value reflect the extension process of *** the cracks develop from the micro scale to the macro scale,the peak frequency tends to be distributed in a lower frequency range,and the b-value decreases *** the peak stress point,the AE energy increases rapidly and the b-value *** specimens without multi-scale fibers exhibit brittle failure,while the specimens with fibers exhibit ductile *** addition,adding multi-scale fibers and crumb rubber increases the peak frequency in the medium and high frequency ranges,indicating a positive effect on inhibiting crack *** being subjected to high temperatures,the maximum and minimum b-values decrease,reflecting an increase in the number of initial cracks due to thermal ***,the RA and AF values are used to classify tensile and shear *** specimens fracture with more shear cracks under compression,and there are more tensile

关键词： multi-scale fibers acoustic emission fracture damage evolution rubberized concrete

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High-speed train positioning based on a combination of Beidou navigation, inertial navigation and an electronic map

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Science China(Information Sciences) 2023年第7期66卷 237-252页

作者： Hui YANG Shuai-Qiang DONG Chun-Hua XIE School of Electrical and Automation Engineering East China Jiaotong University Key Laboratory of Advanced Control & Optimization of Jiangxi Province East China Jiaotong University State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure East China Jiaotong University

To date, the studies on the combination positioning of high-speed trains have made great progress, but the positioning accuracy of these methods is relatively low. Map-matching positioning can improve positioning accuracy, but information transmission is time-consuming. Few studies incorporate it into combination positioning. To solve the problem, this paper proposes a high-speed train positioning method based on combining a Beidou navigation system, an inertial navigation system, and an electronic map. First, the combination positioning problem is transformed into a multi-objective optimization problem, which weights the direction similarity and distance error to form a fitness function and converts the railway line and the maximum error range of each positioning system into constraints. Second, an improved differential evolution algorithm is proposed to solve this problem. By referencing the gray wolf algorithm,the differential evolution algorithm updates individuals by varying toward the direction of multiple optimal values. Then, a new combination positioning algorithm for high-speed trains is proposed. In the simulation,the increase in positioning speed and accuracy is analyzed and validated. Compared to the current algorithms, the proposed algorithm performs better. The proposed method has practical value for improving the reliability and safety of train operations.

关键词： electronic map multi-objective optimization differential evolution algorithm Beidou navigation system high-speed train positioning

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Compression modulus and settlement calculation considering sedimentation and stress history based on single logarithmic unified model

Compression modulus and settlement calculation considering s...

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2021 International Conference on Computational Modeling, Simulation, and Data Analysis, CMSDA 2021

作者： Li, Yi-Xian Cheng, Chao Jin, Chao-Qi Lou, Jia-Yue Zhang, Li-Gang Xu, Chang-Jie Key Laboratory of Geotechnical Engineering Infrastructure Safety and Control in Jiangxi Province East China Jiaotong University Jiangxi Nanchang330013 China Zhejiang Huayun Electric Power Engineering Design and Consultation Co. Ltd. Hangzhou310014 China

ISBN: (纸本)9781510651968

In order to consider the influence of sedimentation and stress history on the settlement calculation and compression modulus, a formula for calculating the compression modulus and settlement of soil was derived based on the unified compression curve of the single logarithm model, and the applicability of the prediction formula was discussed by comparing the existing field monitoring data. Finally, a case study was conducted to explore the evolution of soil compression modulus and settlement under the conditions of sedimentation and stress history. The results show that: (1) For compression modulus, when the additional stress is small, the compression modulus depends on the early consolidation stress. With the increase of additional stress, the influence of the initial consolidation stress becomes less and less, making the compression modulus more and more affected by the additional stress. (2) With the increase of soil depth, the difference of sedimentation on settlement results becomes more obvious. Therefore, when calculating the settlement of deep soil layer, not only the influence of gravity stress, but also the influence of sedimentation on effective weight should be considered. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Sedimentation

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Macro-microscopic deformation evolution of thawing frozen fine-grained soil used in heavy-haul railway subgrades in cold regions

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Research in Cold and Arid Regions 2025年第2期17卷 97-109页

作者： JianBing Chen ShaoJie Liang YuZhi Zhang XiaoDong Zhu Meng Wang MingTao Jia State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions CCCC First Highway Consultants Co.Ltd. School of Civil Engineering Shijiazhuang Tiedao University Structure Health Monitoring and Control Key Laboratory of Hebei Province Shijiazhuang Tiedao University Collaborative Innovation Center for Performance and Safety of Large-Scale Infrastructure Shijiazhuang Tiedao University School of Safety and Emergency Management Shijiazhuang Tiedao University

During the thawing process of a railway subgrade, bidirectional thawing complicates water-heat transfer, leading to serious thaw settlement issues under train loads. Focusing on the severely frozen section of the ShuozhouHuanghua port heavy-haul railway, this study conducted indoor soil-column laterally-limited compression tests on thawing fine-grained soil specimens to analyze the cumulative deformation during thawing. The deformation evolution was examined from both macroscopic and microscopic perspectives. The test results revealed a significant increase in the water content at the frozen interlayer during thawing, with minimal thaw settlement under no-load conditions. However, under dynamic loads, the thawing soil exhibited rapid settlement during the initial stages of the process. Increasing the dynamic load amplitude did not result in significant additional thaw settlement compression. Particle image velocimetry revealed substantial thaw settlement and compression at the top of thawing soil. Microscopically, the porosity at the top of the specimens significantly decreased, whereas the porosity in the frozen interlayer remained largely unchanged. Under dynamic loading, the specimens exhibited a concentrated distribution of large pores with scattered smaller pores. The phase change from ice to water,combined with dynamic loading, induced particle movement and expanded the inter-particle pore space, leading to macroscopic thaw settlement and soil compression. The findings can provide a theoretical foundation for maintaining and ensuring the safety of railway subgrades in cold regions.

关键词： Thawing soil Heavy-haul railway Thaw settlement and compression Particle image velocimetry Microscopic testing

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Uncertainties in landslide susceptibility prediction modeling:A review on the incompleteness of landslide inventory and its influence rules

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Geoscience Frontiers 2024年第6期15卷 80-104页

作者： Faming Huang Daxiong Mao Shui-Hua Jiang Chuangbing Zhou Xuanmei Fan Ziqiang Zeng Filippo Catani Changshi Yu Zhilu Chang Jinsong Huang Bingchen Jiang Yijing Li School of Infrastructure Engineering Nanchang UniversityNanchang 330031China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengduSichuan 610059China Science and Technology Department of Jiangxi Province Nanchang 330046China Department of Geosciences University of PadovaPadovaItaly Information Engineering School Nanchang UniversityNanchang 330031China Discipline of Civil Surveying and Conditioning EngineeringPriority Research Centre for Geotechnical Science and EngineeringUniversity of NewcastleNSWAustralia

Landslide inventory is an indispensable output variable of landslide susceptibility prediction(LSP)***,the influence of landslide inventory incompleteness on LSP and the transfer rules of LSP resulting error in the model have not been *** Xunwu County,China,as an example,the existing landslide inventory is first obtained and assumed to contain all landslide inventory samples under ideal conditions,after which different landslide inventory sample missing conditions are simulated by random *** includes the condition that the landslide inventory samples in the whole study area are missing randomly at the proportions of 10%,20%,30%,40%and 50%,as well as the condition that the landslide inventory samples in the south of Xunwu County are missing in ***,five machine learning models,namely,Random Forest(RF),and Support Vector Machine(SVM),are used to perform ***,the LSP results are evaluated to analyze the LSP uncertainties under various *** addition,this study introduces various interpretability methods of machine learning model to explore the changes in the decision basis of the RF model under various *** show that(1)randomly missing landslide inventory samples at certain proportions(10%–50%)may affect the LSP results for local areas.(2)Aggregation of missing landslide inventory samples may cause significant biases in LSP,particularly in areas where samples are missing.(3)When 50%of landslide samples are missing(either randomly or aggregated),the changes in the decision basis of the RF model are mainly manifested in two aspects:first,the importance ranking of environmental factors slightly differs;second,in regard to LSP modelling in the same test grid unit,the weights of individual model factors may drastically vary.

关键词： Landslide susceptibility prediction Landslide inventory Machine learning interpretability SHapley additive explanations Partial dependence plot

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Effect of Low-intensity Ultrasound on Cd Tolerance of Partial Nitrification Sludge 10

Effect of Low-intensity Ultrasound on Cd Tolerance of Partia...

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10th Annual International Conference on Material Science and Environmental engineering, MSEE 2022

作者： Chen, Peiwen Zhu, Yichun Yang, Jieyuan Lai, Yafen Jiangxi Key Laboratory of Environmental Geotechnical and Engineering Disaster Control Ganzhou341000 China Engineering Technology Research Center for Water Quality Safety Assurance of Ganjiang River Basin Jiangxi University of Science and Technology Ganzhou341000 China

Cadmium (Cd) is a typical nitrification inhibitor, which has a strong inhibitory effect on partial nitrification (PN). The discrepancy on Cd tolerance of PN sludge caused by low-intensity ultrasound (LIU) was studied. It suggested that the half inhibitory concentration (IC50) of sludge was increased from 24.51 to 29.07 mg/L by 35 days of ultrasonic treatment, and the Cd tolerance of sludge was enhanced. Further analysis indicated that contents of extracellular polymeric substances (EPS) rose substantially because of LIU, which played a catalytic role on increasing adsorption capacity of PN sludge for Cd. © Published under licence by IOP Publishing Ltd.

关键词： Nitrification

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Attenuation characteristics of impact-induced seismic wave in deep tunnels:An in situ investigation based on pendulum impact test

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Journal of Rock Mechanics and geotechnical engineering 2022年第2期14卷 494-504页

作者： Jian Wu Quansheng Liu Xiaoping Zhang Chuiyi Zhou Xin Yin Weiqiang Xie Xu Liang Jiaqi Huang PowerChina Huadong Engineering Corporation Limited Hangzhou311122China Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province School of Civil EngineeringWuhan UniversityWuhan430072China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China Hangzhou Urban Infrastructure Construction Management Center Hangzhou310009China

The radiated seismic energy is an important index for the intensity assessment of microseismic(MS)events and the early warning of dynamic ***,the energy of MS signals is significantly attenuated due to the heterogeneity and viscous damping of rock ***,the study on attenuation characteristics of MS signals in underground engineering has practical significance for the accurately estimation of radiated seismic *** on a pendulum impact test facility and MS monitoring system,an in situ investigation was carried out to explore attenuation characteristics at a deep *** results show that the seismic energy and peak particle velocity(PPV)attenuation are exponentially related to the propagation *** attenuation coefficient of energy is larger than that of *** the increase in the input impact-energy,the seismic energy attenuation coefficient decreases as a power *** empirical relationship between energy attenuation coefficient and wave impedance of rock mass was established in this ***,the time-frequency characteristics and energy distribution laws of impact-induced signals were investigated by the continuous wavelet transform(CWT)and wavelet packet analyses,*** dominant frequency of signals decreases gradually as the propagation distance *** on the energy attenuation characteristics,a new method was proposed to calculate the released source energy of MS events in the *** study can provide an insight into energy attenuation characteristics of seismic waves and references for attenuation correction in seismic energy calculation.

关键词： Attenuation characteristics Microseismic monitoring Pendulum impact facility Seismic energy Deep tunnels

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Data-Driven Intersection safety Evaluation Methodology and Analysis 23

Data-Driven Intersection Safety Evaluation Methodology and A...

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23rd COTA International Conference of Transportation Professionals: Emerging Data-Driven Sustainable Technological Innovation in Transportation, CICTP 2023

作者： Wu, Pingping Lu, Guangquan Liu, Miaomiao Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control School of Transportation Science and Engineering Beihang Univ. Beijing China Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control School of Transportation Science and Engineering Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang Univ. Beijing China Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies Southeast Univ. Nanjing China

ISBN: (数字)9780784485040

ISBN: (纸本)9780784485040

With the development of information and sensing technologies, a wide variety of intersection traffic data is available. The purpose of this paper is to make full use of video and commercial vehicle trajectory data to deeply explore the intersection safety status. In this paper, based on different sample sizes, different sampling frequencies, and different accuracies of data, the safety analysis of intersections is carried out from micro and macro aspects based on post-encroachment time (PET) and vehicle deceleration behavior, respectively. On the one hand, we use the full-sample and high-precision trajectory data extracted from video to analyze the safety of each region of intersection based on PET. On the other hand, using the trajectory data with low penetration rate and low sampling frequency extracted from the positioning data of the online car-hailing, a distribution fit, and non-parametric test are conducted for the vehicle deceleration behavior, and then the overall safety state of the intersection is evaluated. The results can provide ideas for the identification of intersection risk points and the application of different kinds of data on intersection safety evaluation. © ASCE.

关键词： Commercial vehicles

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Seismic Target Drifts for Underground Railway Stations. Cases of Traditional Rigid Connections and Sliding Interior Columns

SSRN

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SSRN 2023年

作者： Bu, Xiangbo Xu, Zigang Ledesma, Alberto López-Almansa, Francesc Civil and Environmental Engineering Department Barcelona Spain Jiangxi Key Laboratory of Infrastructure Safety Control in Geotechnical Engineering East China Jiaotong University Nanchang China Architecture Technology Department Barcelona Spain

In this study, the seismic performances of underground structures with either transverse traditional rigid layout or sliding interior columns are numerically evaluated by pushover analyses;both the horizontal and vertical components of the seismic ground motion are taken into account. Thirty-one representative actual subway stations featured with various structural forms, soil types, and burial depths are analyzed in this study;although each of these stations has rigid connections between all their structural members, alternative solutions with sliding interior columns are also designed. The seismic performance of each station (with rigid connections and sliding columns) is evaluated in the framework of the Performance-Based Design by considering four Target Drifts: Normal Operational, Immediate Operational, Reparable Operational and Irreparable. The corresponding drift thresholds are determined for each individual station, then global average values for the two considered cases (traditional rigid layout and sliding columns) are proposed. The rationality of the proposed seismic performance quantification system is verified by comparison with observed damage (Daikai station, traditional rigid solution) and experimental results (shaking table test of reduced scale station model with sliding columns). © 2023, The Authors. All rights reserved.

关键词： Underground structures

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