Development of pile foundation with high ductility aseismic joints

高延性抗震缝桩基础的研制

基本信息

批准号：
07555441
负责人：
MIURA Fusanori
金额：
$ 0.45万
依托单位：
Yamaguchi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555441/
关键词：
Pile foundation Aseismic joint Ductility Liquefaction Lateral spreading Response of pile Large deformation analyzes 地盤の側方移動曲げ載荷実験数値解析大変形

项目摘要

We developed a High Ductility Aseismic Jointed (HDAJ) Pile at the first stage of this study. We performed bending tests to investigate the bending moment-deflection relationships of the pile. Then we developed nonlinear finite element analysis program which can analyze the large deformation analysis. The validity of the nonlinear FEM was conformed by simulating the experimental results. Next, we modified the original HDAJ pile (X-type) to give more ductility (Y-type).We performed parametric study to examine the effect of splicer types (X-type, Y-type), stratum thickness, pile cap connectivity, pile tip embedment depth etc.on the spilced piles when subjected to large ground deformation caused by liquefaction. In all cases, we found that HDAJ piles were effective (Y-type is more effective than X-type) compared with ordinal pile for liquefaction-induced large lateral ground displacements. At the same time, we found that the failure mechanism of piles could be categorized into 6 patterns.In the second stage, we performed dynamic analyzes of the HDJA piles to investigate the seismic response characteristics. The HDAJ piles are more flexible than ordinal piles, therefore, the seismic responses of HDAJ may greater than those of ordinal piles. This is the reason why we performed the seismic response analyzes. But the responses, such as the maximum acceleration, velocity and displacement, of HDAJ piles to strong earthquake motions were no more than those of ordinal piles. Besides, the maximum bending moment induced in piles were greatly reduced. This means that the HDAJ piles are also effective during strong earthquake motions.

在这项研究的第一阶段，我们开发了高延展性的无性接合（HDAJ）桩。我们进行了弯曲测试，以研究桩的弯曲力矩反射关系。然后，我们开发了非线性有限元分析程序，该程序可以分析大型变形分析。非线性FEM的有效性通过模拟实验结果符合。接下来，我们修改了原始的HDAJ桩（X型）以给出更多的延展性（Y-Type）。我们进行了参数研究，以检查剪接类型（X-Type，Y-type）的影响，地层厚度，桩帽连接性，桩帽连接性，堆积型嵌入深度等因对大型地面降低而受到大量地面降低而导致的稀疏性。在所有情况下，我们都发现与液化诱导的大型侧面位移相比，HDAJ桩有效（Y型比X型更有效）。同时，我们发现桩的故障机理可以分为6个模式。在第二阶段，我们对HDJA桩进行了动态分析，以研究地震响应特征。 HDAJ桩比顺序桩更灵活，因此，HDAJ的地震反应可能大于序桩的地震反应。这就是我们进行地震反应分析的原因。但是，HDAJ桩对强烈地震运动的最大加速度，速度和位移等反应不只是序数桩的反应。此外，桩中诱导的最大弯矩大大减少了。这意味着HDAJ桩在强烈的地震运动中也有效。