Behavior of piled raft foundations subjected to static horizontal loading and seismic loading

桩筏基础在静水平荷载和地震荷载作用下的性能

基本信息

批准号：
12450188
负责人：
MATSUMOTO Tatsunori
金额：
$ 7.04万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450188/
关键词：
Piled raft Pile Centrifuge modeling Laboratory model test Horizontal resistance Earthquake-proof Sand Deformation analysis

项目摘要

The main objectives of this research are 1) provide comprehensive experimental data for pile rafts subjected to static horizontal loads and dynamic (seismic) loads for design of piled raft foundations, 2) develop a simple but workable analytical method for deformation and load proportion of pile rafts and pile groups. To achieve these objectives, a series of centrifuge modeling of pile rafts was extensively conducted and some conclusions are shown below:1. The stiffness and the ultimate resistance of the single pile in the piled raft are highly different from those observed in the loading test of the isolated single pile. The increase in the confining stress around the pile due to the load transferred through the raft base should be considered in the evaluation of the pile response in the piled raft design, as well as the interaction effects between the components.2. The ultimate frictional resistance of the raft component in the piled raft was smaller (rigid pile head connection) or a … More lmost the same (hinged pile head connection) compared with the estimates from the raft vertical loads and the coefficient of the friction between the raft base and the soil. It was thought that the soil beneath the raft was constrained by the piles which may reduce the shear deformation of the soil just beneath the raft base, and thus the mobilized shear stress at the interface was smaller.3. As for the proportion of the horizontal load carried by each component, the raft initially carried more load than the piles, with larger displacements the piles more than the raft in the piled raft with rigid pile head connection. In the piled raft with hinged pile head connection, the contribution of the piles was much smaller. Overall, however, the proportion is highly dependent on the piled raft displacement, and it is therefore important to consider such non-linear response in the designs of piled raft foundations.4. In the piled raft designs, evaluation of the displacement (settlement, horizontal displacement, and inclination) and the proportion of the load carried by the components are the most important factors. The dynamic behaviors of the above factors were intensively examined in this paper.5. The change in the vertical load sharing between the piles and the raft base was relatively small compared with the horizontal load, even when the piled rafts were subjected to relatively strong input motion. Less

这项研究的主要目的是1）为堆积的水平载荷和动态（地震）载荷提供堆积的桩的全面实验数据，以设计堆积的木筏基础，2）开发一种简单但有效的分析方法，用于变形和负载比例的桩柱和桩组的载荷比例。为了实现这些目标，广泛进行了桩筏的一系列离心机建模，下面显示了一些结论：1。堆积筏中单个桩的刚度和最终电阻与在孤立的单个桩的加载测试中观察到的刚度高度不同。在评估堆积的筏设计中堆积反应以及组件之间的相互作用效果时，应考虑由于通过筏底座传递的载荷引起的桩周围束应力的增加。2。与筏垂直载荷的估计值以及筏碱基和土壤之间的摩擦核心相比，堆积筏中筏的最终摩擦电阻较小（刚性桩头连接）或…最大的（铰链桩头连接）。据认为，筏下面的土壤受到钢琴的约束，这可能会减少筏底下土壤的剪切变形，因此界面处的动员剪切应力较小。3。至于每个组件所承载的水平载荷的比例，筏最初比钢琴承载更多的负载，钢琴的位移比堆积的木筏更大的钢琴较大，并具有刚性的桩头连接。在带有铰链头部连接的堆积筏中，钢琴的贡献要小得多。然而，总体而言，该比例高度取决于堆积的筏位移，因此重要的是考虑在堆积筏基础的设计中考虑这种非线性响应。4。在堆积的筏设计中，评估位移（沉降，水平位移和倾斜度）以及组件携带的负载比例是最重要的因素。在本文中对上述因素的动态行为进行了深入研究。5。与水平载荷相比，钢琴和木筏底座之间的垂直负载共享的变化也相对较小，即使堆积的筏相互互相进行以强烈输入运动。较少的