检索结果-南通市图书馆

Collapse of a Deep Excavated Foundation Pit in the Soft Soils by 3-D FEM

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2019年第1期36卷 162-174页

作者： zhuang haiyang XUE Xuchao YU Xu Institute of Geotechnical Engineering Shandong University Institute of Geotechnical Engineering Nanjing Tech University School of Architecture Engineering Nanjing Institute of Technology

In view of the collapse of a deep excavated foundation pit of the Xianghu subway underground station in Hangzhou of China,the main features of the accident are analyzed,and the induced factors of the accident are summarized. Then,a 3-D FEM analysis model is created to demonstrate the soil-support structures interaction system,and the effect of the main factors,such as the volume replacement ratio of the bottom soil reinforcing,the asymmetric ground overload,the embedded depth of the diaphragm wall,the shear strength of the bottom soils disturbed by the construction,and the excessive excavation of the bottom soil,are analyzed and compared. The results show that the ineffective original reinforcement plan for the bottom soft soil is the most prominent factor for the accident,and the disturbance effect of the deep excavation on the shear strength of the bottom soft soil is another significant factor for the accident. Meanwhile,if the reinforcement of the bottom soft soil is canceled,an appropriate extension of the diaphragm retaining walls to the under lying harder soil layer can also effectively prevent the collapse of the deep excavated foundation pit. In addition,the partly excessive excavation in the process has a great influence on the axial force of the most nearby horizontal support but few effect on the stability of the diaphragm wall. Thus,the excessive excavation of the bottom soils should not be the direct inducing factor for the accident. To the asymmetric ground overload,it should be the main factor inducing the different damage conditions of the diaphragm walls on different sides. According to the numerical modeling and actual engineering accident condition,the development process of the accident is also identified.

关键词： deep excavation subway station collapse process numerical modeling soft soil

Shaking Table Model Test of Isolated Structure on Soft Site and Analysis on Its Isolation Efficiency

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2017年第2期34卷 169-176页

作者： Yu Xu zhuang haiyang Zhu Chao Department of Civil Engineering Nanjing Institute of Technology Institute of Geotechnical Engineering Nanjing University of Technology

Adopting a soft site model built on soft interlayer soil foundation,a shaking table test for soft interlayer soil-isolated structure interaction is conducted to investigate the seismic response of isolated structure on soft site,and analyze its isolation *** results show that the test can reflect the earthquake response characteristics of isolated structure on soft *** is on soft site that the dynamic characteristics of isolated structure,acceleration magnification factor(AMF)of isolated structure and isolation efficiency of the isolation layer differ from those on rigid foundation with an soil-structure interaction(SSI)effect,represented by the reduction in fundamental vibration frequency of isolated structure and the increase of damping ratio with changes of the SSI *** can either increase or decrease AMF of isolated structure on soft site,depending on the characteristics of earthquake motion ***,the isolation efficiency of isolation layer on soft site is decreased with the SSI effect,which is related to the peak ground acceleration(PGA)and the characteristics of earthquake motion input.

关键词： isolated structure shaking table model test soil-structure interaction(SSI) seismic response isolation efficiency

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

在线全文

学校读者我要写书评

暂无评论

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

Bilayer Structured Nanowire-array and Nanotube-cluster TiO2 Photoanode for Efficient Dye-sensitized Solar Cells

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2015年第3期31卷 412-417页

作者： YU Jun ZHANG Chengkai zhuang Jia QIN haiyang HE Quangui LIANG Qiumei School of Materials Science and Engineering Southwest Petroleum University Chengdu 610500 P.R.China

Nanowire-array nanotube-cluster bilayer TiO2 films, consisting of nanowire-array at the bottom layer and nanotube-cluster at the top layer were prepared via a two-step hydrothermal method. One step was a growth process and the other was an etching process. Etching process was used to acquire nanowire-array with a small diameter of 20--25 nm of the nanowire and nanotube-cluster. The bilayer nanostructured films were then modified with TiCI4. Villous TiO2 attached to both the inside and outside wails of the nanotube cluster was obtained only by changing the traditional concentration of TiCla-treatment to 0.2 mol/L. The novel bilayer photoanode finally revealed a higher effi- ciency of 5.25% when used in dye-sensitized solar cells（DSSCs）.

关键词： Bilayer structure Etching Titanium oxide Photoanode Dye-sensitized solar cell

Numerical simulation of irregular section underground structure shaking table test model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Research Advances 2022年第4期2卷 53-59页

作者： Baizan Tang Wenchao Deng Su Chen Xiaojun Li haiyang zhuang State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang330013China Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin150086China Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing100124China

Based on the the large shaking table test results on irregular section subway station structure in soft soil,an overall time-history numerical simulation is conducted to study the nonlinear dynamic interaction of the soilirregular underground *** test results,including the acceleration of the soil,acceleration,and deformation of the structure,were *** consistency between the simulation and test results is verified,and the difference between these results was discussed in *** maximum inter-story drift ratio was approximately 1/472 under input PGA=0.54 *** strain responses of columns were significantly larger than those of the side walls and *** components in the lower layers of the irregular subway station structure,particularly in the central columns,underwent cumulative *** research results could provide a simplified analysis method to quantitatively evaluate the damage of irregular underground structures in soft soil.

关键词： Irregular section subway station Soft soil Seismic response Numerical simulation Shaking table test

Numerical investigation on seismic performance of a shallow buried underground structure with isolation devices

在线全文

学校读者我要写书评

暂无评论

Earthquake Research Advances 2022年第4期2卷 11-21页

作者： Jianning Wang Guangyu Zhang haiyang zhuang Jing Yang Chen Li Beijing Materials Handling Research Institute Co Ltd.Beijing100007China China National Machinery Industry Co Ltd.Beijing100080China Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing210009China China Construction Sixth Engineering Bureau Corp Ltd.Tianjin210009China

A design procedure for improving the seismic performance of unequal-span underground structures by installing isolation devices at the top end of columns is proposed based on the seismic failure mode of frame-type underground structures and the design concept of critical support columns.A two-dimensional finite element model(FEM)for a soil-underground structure with an unequal-span interaction system was established to shed light on the effects of a complex subway station with elastic sliding bearings(ESB)and lead rubber bearings(LRB)on seismic *** was found that the stiffness and internal force distribution of the underground structure changed remarkably with the installation of isolation devices at the top end of the *** constraints of the beam-column joints were significantly weakened,resulting in a decrease in the overall lateral stiffness and an increase in the structural lateral *** introduction of the isolation device effectively reduces the internal force and seismic damage of the frame column;however,the tensile damage to the isolation structure,such as the roof,bottom plate,and sidewall,significantly increased compared to those of the non-isolation *** the relative slip of the ESB remains within a controllable range under strong earthquake excitation as well as frame columns with stable vertical support and self-restoration functions,the LRB shows a better performance during seismic failure and better lateral displacement response of the unequal-span underground *** analysis results provide new ideas and references for promoting the application of seismic isolation technology in underground structures.

关键词： Underground structure Seismic performance Isolation device Elastic sliding bearing Lead rubber bearing Soil-structure interaction

Seismic performance of two-story subway station structures with different isolating systems

在线全文

学校读者我要写书评

暂无评论

Earthquake Research Advances 2022年第4期2卷 60-71页

作者： haiyang zhuang Wei Wang Liguo Jin Sheng Li Guoxing Chen School of Civil Engineering and Architecture East China Jiaotong UniversityNanchang330013China Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province Nanjing210009China Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing210009China Institute of Geophysics China Earthquake AdministrationBeijing100081China

When the sliding bearing is fixed only at the top of the middle column of the underground structure,the cracks at the side end of the middle plate should be aggravated while the seismic damage of the mid-column should be *** enhance the seismic performance of the mid-plate,a new isolation design method has been mentioned while the elastic sliding bearings are set at the top of the mid-columns and between the side end of the mid-plate and the side wall at the same *** establishing a nonlinear finite element analysis model for the static-dynamic coupling interaction system,the seismic response characteristics of the cast-in-place station structure without a sliding bearing have been analyzed and compared with those of the station structure with the sliding bearing fixed only at the top of the middle columns,and those of the station structure with sliding bearing be fixed between the mid-plate and the sidewall at the same *** results show that the new isolation station structures suffer fewer earthquake damages at the mid-plate and mid-columns at the same time,which can improve the overall seismic performance of the subway station structure.

关键词： Subway station structure Seismic performance Elastic sliding bearing Seismic mitigation effect Numerical modelling

Effects of Initial Static Shear Stress and Grain Shape on Liquefaction of Saturated Nanjing Sand

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2021年第1期38卷 44-56页

作者： zhuang haiyang PAN Shuxuan LIU Qifei YU Xu Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing 210009P.R.China School of Architecture Engineering Nanjing Institute of TechnologyNanjing 211167P.R.China

This paper mainly investigates the effects of initial static shear stress and grain shape on the liquefaction induced large deformation of saturated sand under torsional *** sand,mainly composed of platy grains,is tested with different initial static shear stress ratio(SSR)using a hollow column torsional shear *** tests find that the saturated Nanjing sand reaches full liquefaction under the superposition of initial static shear stress and cyclic stress for both stress reversal and non-reversal ***,it requires a large number of loading cycles to reach full liquefaction if stress reversal does not *** increasing the initial static stress,the large deformation of the Nanjing sand should mainly induced by the cyclic liquefaction firstly under a smaller initial shear stress,and then it should be induced by the residual deformation *** critical point occurs approximately when the initial shear stress is close to the amplitude of the cyclic shear ***,it shows that grain angularity increases the liquefaction resistance when the initial static shear stress is zero.A small initial static shear stress causes the larger loss of liquefaction resistance for angular sand than rounded *** a high initial SSR,the angular sand is more resistant to the large residual deformation failure than the rounded sand.

关键词： Nanjing sand liquefaction initial shear stress grain shape residual deformation failure

Dynamic Interaction of Soil-Isolated Structure:A Systematic Review

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2020年第1期37卷 40-53页

作者： YU Xu WU Xiaofei ZHU Mingxuan zhuang haiyang Department of Civil Engineering Nanjing Institute of TechnologyNanjing 211167P.R.China Institute of Geotechnical Engineering Nanjing University of TechnologyNanjing 210009P.R.China Nanjing Jiangning Economic Technology Development General Company Nanjing 211167P.R.China

Isolation technique of ground structure is a hot topic in the field of earthquake engineering and structure *** soil-isolated structure dynamic interaction study is of great significance to enhance seismic performance of isolated structures and revision of relevant isolation specifications,research on dynamic interaction of soil-isolated structure has attracted more and more *** on the basic theory of soil-structure dynamic interaction,we summarize and analyze the research status quo of soil-isolated structure dynamic interaction by means of theoretical analysis,numerical simulation,model test,prototype observation and seismic *** reviewing the results of previous research,we reveal that some key issues,which can be used to uncover dynamic interaction mechanism and seismic response characteristics of soil-isolated structures interaction system,should not be *** on the concept of seismic performance design and the latest research of soil-isolated structure dynamic interaction,we predict the future development of soil-isolated structure dynamic interaction by elastoplastic time history analysis method,seismic performance level and practical analysis method based on energy.

关键词： isolated structure earthquake resistance soil-structure interaction