权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Effects of soil liquefaction on horizontal subgrade reaction of pile during earthquakes

地震作用下土体液化对桩水平路基反应的影响

基本信息

批准号：
62460166
负责人：
TOKIMATSU Kohji
金额：
$ 4.22万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1989
项目状态：
已结题

项目摘要

Shaking table tests were conducted to study dynamic soil-pile- structure interaction during soil liquefaction. A model sand deposit-pile-structure system was constructed in a large container 4m long, 2m wide and 2 m deep. The container, consisting of stacked steel plates, can allow shear deformation of the soil. Shaking table liquefaction tests were then conducted in which soil density, pile diameter, pile rigidity, thickness of the liquefied layer and input motion were controlling variables. Pore pressure, acceleration, and deformation of soil-pile-structure system, and bending moment of pile were monitored and recorded during the test.The analysis of shaking table test results together with the basic information indicated that: (1) regardless of the rigidity of pile, the dynamic response of the soil-structure system before liquefaction is significantly influenced by the response of soil deposit, (2) unless the pile is rigid enough, the dynamic response of the soil-structure system after liquefaction is also influenced by the response of soil, and (3) the maximum bending moment of the pile is related better to the maximum deformation of the ground surface than to maximum accelerations measured on the structure and the ground surface.In order to simulate the above findings, analytical method was developed in which regradation of the coefficient of horizontal subgrade reaction of pile due to liquefaction is taken into account as well as the regradation of soil modulus. Analysis was made for both liquefied and non-liquefied cases, and the results were compared with the measured values. The analytical results including the time histories of acceleration, displacement, and bending moment of pile, and the response spectra of the ground surface and structure, are all in good accord with the observed values, showing that the model used in the analysis is reasonable.

进行振动台试验来研究土壤液化过程中的动态土-桩-结构相互作用。在长4m、宽2m、深2m的大型容器内建造了模型砂堆积-桩-结构系统。该容器由钢板堆叠而成，可以允许土壤发生剪切变形。然后进行振动台液化试验，其中土体密度、桩直径、桩刚度、液化层厚度和输入运动为控制变量。试验过程中对土-桩-结构体系的孔隙压力、加速度、变形以及桩的弯矩进行了监测和记录。振动台试验结果与基本信息分析表明：（1）无论桩的刚度如何，液化前土-结构体系的动力响应都受到土沉积物响应的显着影响；（2）除非桩有足够的刚性，液化后土-结构体系的动力响应将受到显着影响。液化还受到土体响应的影响，(3)桩的最大弯矩与地表最大变形的相关性比与结构和地表测得的最大加速度的相关性更好。为了模拟上述发现，开发了分析方法，其中考虑了液化引起的桩水平路基反力系数的再分级以及土模量的再分级。对液化和非液化两种情况进行分析，并将结果与测量值进行比较。桩的加速度、位移、弯矩时程以及地表和结构的响应谱等分析结果与观测值吻合较好，表明分析所采用的模型是合理的。