The pile-soil system interaction computational model in liquefaction-induced lateral spreading ground was established by the finite difference numerical method.Considering an elastic-plastic subgrade reaction method,n...The pile-soil system interaction computational model in liquefaction-induced lateral spreading ground was established by the finite difference numerical method.Considering an elastic-plastic subgrade reaction method,numerical methods involving finite difference approach of pile in liquefaction-induced lateral spreading ground were derived and implemented into a finite difference program.Based on the monotonic loading tests on saturated sand after liquefaction,the liquefaction lateral deformation of the site where group piles are located was predicted.The effects of lateral ground deformation after liquefaction on a group of pile foundations were studied using the fmite difference program mentioned above,and the failure mechanism of group piles in liquefaction-induced lateral spreading ground was obtained.The applicability of the program was preliminarily verified.The results show that the bending moments at the interfaces between liquefied and non-liquefied soil layers are larger than those at the pile＇s top when the pile＇s top is embedded.The value of the additional static bending moment is larger than the peak dynamic bending moment during the earthquake,so in the pile foundation design,more than the superstructure＇s dynamics should be considered and the effect of lateral ground deformation on pile foundations cannot be neglected.展开更多
Geosynthetic-reinforced and pile-supported （GRPS） embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are expos...Geosynthetic-reinforced and pile-supported （GRPS） embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are exposed through a lot of applications on conventional technique of GRPS embankment （called CT embankment）, i.e., intolerable settlement and lateral displacement, low geosynthetic efficiency, etc. In view of these disadvantages, the fixed geosynthetic technique of GRPS embankment （called FGT embankment） is developed in this work. In this system, the geosynthetic is fixed on the pile head by the steel bar fulcrum and concrete fixed top. The principles and construction techniques involved in the FGT embankment are described firstly. Then, the numerical analysis method and two-stage analysis method are used to study the performance of FGT embankment, respectively. It is shown that the FGT embankment can provide a better improvement technique to construct a high embankment over soft ground.展开更多
The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements o...The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements of structures.These openings may negatively impact the lateral stiffness of steel plate shear walls.Therefore,an experimental research was instituted to investigate the seismic behavior of steel plate shear walls,with and without openings.The experimental results showed that steel plate shear walls have the satisfying seismic behavior,and,as expected,the strength and stiffness characteristics of the walls were reduced due to openings.Then a single-story wall panel FE model and an analytical deep beam model are developed in order to find the critical factors dominating the thickness reduction coefficient of wall panels with the opening.Furthermore,extensive parametric analysis is conducted to derive a simplified formula for the determination of the thickness reduction coefficient of wall panels with the opening for substituting solid wall panels with reduced thickness for actual wall panels with the opening.Finally,the design method for calculating the lateral stiffness is verified by some experimental programs and recommended for the routine practice of steel plate shear walls.展开更多
基金Project(51109208)supported by the National Natural Science Foundation of ChinaProject(2013M531688)supported by the Postdoctoral Science Foundation of China+1 种基金Project(Z012009)supported by the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering(Institute of Rock and Soil Mechanics,Chinese Academy of Sciences)Project(CKSF2012054)supported by the Foundation of Changjiang River Scientific Research Institute,China
文摘The pile-soil system interaction computational model in liquefaction-induced lateral spreading ground was established by the finite difference numerical method.Considering an elastic-plastic subgrade reaction method,numerical methods involving finite difference approach of pile in liquefaction-induced lateral spreading ground were derived and implemented into a finite difference program.Based on the monotonic loading tests on saturated sand after liquefaction,the liquefaction lateral deformation of the site where group piles are located was predicted.The effects of lateral ground deformation after liquefaction on a group of pile foundations were studied using the fmite difference program mentioned above,and the failure mechanism of group piles in liquefaction-induced lateral spreading ground was obtained.The applicability of the program was preliminarily verified.The results show that the bending moments at the interfaces between liquefied and non-liquefied soil layers are larger than those at the pile＇s top when the pile＇s top is embedded.The value of the additional static bending moment is larger than the peak dynamic bending moment during the earthquake,so in the pile foundation design,more than the superstructure＇s dynamics should be considered and the effect of lateral ground deformation on pile foundations cannot be neglected.
基金Foundation item： Project（51278216） supported by the National Natural Science Foundation of China Project（11-2-05） supported by the Scientific and Technological Project for Shanxi Communication Construction, China Project（HF-08-01-2011-240） supported by the Graduates＇ Innovation Fund of Huazhong University of Science and Technology, China
文摘Geosynthetic-reinforced and pile-supported （GRPS） embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are exposed through a lot of applications on conventional technique of GRPS embankment （called CT embankment）, i.e., intolerable settlement and lateral displacement, low geosynthetic efficiency, etc. In view of these disadvantages, the fixed geosynthetic technique of GRPS embankment （called FGT embankment） is developed in this work. In this system, the geosynthetic is fixed on the pile head by the steel bar fulcrum and concrete fixed top. The principles and construction techniques involved in the FGT embankment are described firstly. Then, the numerical analysis method and two-stage analysis method are used to study the performance of FGT embankment, respectively. It is shown that the FGT embankment can provide a better improvement technique to construct a high embankment over soft ground.
基金supported by the National Key Technology R&D Program of China(Grant No.2011BAJ09B01)the National Natural Science Foundation of China(Grant Nos.51178246,51222810)Tsinghua University Initiative Scientific Research Program(Grant No.20101081766)
文摘The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements of structures.These openings may negatively impact the lateral stiffness of steel plate shear walls.Therefore,an experimental research was instituted to investigate the seismic behavior of steel plate shear walls,with and without openings.The experimental results showed that steel plate shear walls have the satisfying seismic behavior,and,as expected,the strength and stiffness characteristics of the walls were reduced due to openings.Then a single-story wall panel FE model and an analytical deep beam model are developed in order to find the critical factors dominating the thickness reduction coefficient of wall panels with the opening.Furthermore,extensive parametric analysis is conducted to derive a simplified formula for the determination of the thickness reduction coefficient of wall panels with the opening for substituting solid wall panels with reduced thickness for actual wall panels with the opening.Finally,the design method for calculating the lateral stiffness is verified by some experimental programs and recommended for the routine practice of steel plate shear walls.
