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

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.

在本研究的第一阶段，我们开发了一种高延性抗震连接桩。我们进行了弯曲试验，以研究桩的弯矩-挠度关系。在此基础上，开发了能够进行大变形分析的非线性有限元分析程序。仿真结果验证了非线性有限元法的有效性。接下来，我们对原来的HDAJ桩（x型）进行了修改，使其具有更大的延性（y型）。通过参数化研究，考察了接插件类型（x型、y型）、地层厚度、承台连通性、桩端嵌入深度等因素对液化引起的地面大变形下的分岔桩的影响。在所有情况下，我们发现HDAJ桩比普通桩更有效（y型比x型更有效）用于液化引起的大侧向地面位移。同时，我们发现桩的破坏机制可分为6种模式。在第二阶段，我们对HDJA桩进行了动力分析，以研究其地震反应特征。HDAJ桩比普通桩具有更大的弹性，因此HDAJ桩的地震反应可能比普通桩大。这就是我们进行地震反应分析的原因。但HDAJ桩对强震运动的最大加速度、最大速度和最大位移等响应并不比普通桩多。同时大大降低了桩身最大弯矩。这意味着HDAJ桩在强震运动中也是有效的。