An Investigation on Dynamic Stability of Soft Clay Improved by Sand Compaction Piles

压实砂桩改善软土动力稳定性研究

基本信息

批准号：
63420041
负责人：
KIMURA Tsutomu
金额：
$ 6.78万
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 (A)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

A series of dynamic model tests was conducted to study the dynamic response of soft clay improved by sand compaction piles(S.C.P.) by using a newly developed shaker using a linear way system. The improved ground is subjected to caisson loading. Parameters considered in this study were the area ratio and the width of S.C.P. improvement, the magnitude of horizontal seismicity and the duration of vibration.Conclusions derived from this study are as follows. 1. The ratio of the stress in a pile to that of clay in improved ground reduces when the ground is subjected to an earthquake. However, the ratio increases after the earthquake. 2.The ratio of acceleration at the bottom of a caisson to the input acceleration is closely related to the rigidity of ground. At the initial stages of an earthquake, the ratio is much higher for improved ground than that for ground without improvement. However, the difference becomes smaller with the progress of the earthquake, implying that the improved ground loses rigidity by being subjected to vibration. 3. When the static safety factor is identical for improved ground and non-improved ground, larger settlements take place for the latter when they are subjected to vibration. The settlements are greater for higher seismicity and longer vibration duration. T he correlation between the settlements and the dynamic safety factor calculated with the conventional pseudo-dynamic stability analysis is satisfactory.

进行了一系列动态模型测试，以研究通过使用线性方式系统使用新开发的振动器改善沙子压实桩（S.C.P。）的软粘土的动态响应。改进的地面受到凯森的负载。本研究中考虑的参数是S.C.P.面积比和宽度。改进，水平地震性的幅度和振动的持续时间。从这项研究中得出的结论如下。 1。当地面发生地震时，桩中的应力与粘土的应力之比减少了。但是，地震后的比率增加。 2.凯森（Caisson）底部的加速度与输入加速度的比率与地面的刚度密切相关。在地震的初始阶段，改进地面的比率要比地面高得多。但是，随着地震的进展，差异变得较小，这表明改善的地面会因受到振动而失去刚性。 3。当静态安全系数相同以改善地面和未经改进的地面时，后者发生振动时会发生较大的定居点。对于更高的地震性和更长的振动持续时间，这些定居点更大。通过常规伪动态稳定性分析计算的定居点与动态安全因子之间的相关性是令人满意的。