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基本信息

批准号：
04650432
负责人：
TAKEMURA Jiro
金额：
$ 1.28万
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 (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650432/
关键词：
Two layred ground Sand Clay Bearing capacity Deformation Centrifuge model test 砂地盤

项目摘要

Centrifuge model tests were carried out to investigate bearing capacities and deformations of two layred soil in whicha sand oelies a relatively soft clay. Non-dimensional parameters which might directy influence on these phenomena were derived from dimensional analysis. Centrifuge tests were divided into two series. One is bearing capacity tests which were conducted under constant loading rate by using strip and circular footing, and the other is consolidation tests in which model grounds were subjected to a constant load less than its bearing capacity through a circular footing. All test were conducted under 100g and constant thickness of clay laer varying with ratios of the thickness of sand to the footing width, H/B.Following conclusions are derived from this study.(1) Normalized bearing capacity, 2qf/ gammaB, is found to be a function of H/B, and pO/ gammaB, where gamma is effective unit weight, cu the undrained shear strength f underlying clay, cu/ gamma B normalized bearing capacity of clay and pO/gB normalized overburden resssure. The 2qf/ gammaB increases linearly with cu/ gammaB and pO/ gammaB under constant H/B.(2) The bearing capacity of the two layred soil increases with H/B until it becomes the bearing capacity of the uniform infinite sand layr. The value of H/B over which the bearing capacity is constant in that of the infinite sand, (H/B)**, is about 1.5 to 2 for circular footing and 4 for strip footing.(3) Failure mechanisms of the two layred soil can be classified into two categories ; one is general faiure in sand layr which occurred for (H/B)** and the other is punching failure forming a block of sand beneath the footing for H/B smaller than (H/B)**.(4) Consolidation of the two layred soil under constant load increases with its intensity. A single uique relationship was found between the ratios of applied load intensities to beaing capacities and consolidation settlements in the grounds with H/B of 1.0 to 2.0.

进行离心模型测试，以研究两种层状土壤的轴承能力和变形，其中砂面是相对柔软的粘土。可能导致对这些现象影响的非二维参数来自维度分析。离心测试分为两个系列。一个是使用带状和圆形的轴承测试在恒定载荷速率下进行的轴承能力测试，另一个是合并测试，其中模型地面的恒定负载小于其通过圆形的轴承容量小于其轴承容量。所有测试均在100克以下进行，粘土laer的恒定厚度随沙子厚度与基础宽度的比率变化，H/B。遵循的结论是从这项研究中得出的。要成为h/ b和po/ gammab的函数，伽玛是有效的单位重量，cu不排水的剪切强度f下面的粘土，Cu/ gamma b标准化粘土的轴承能力和PO/ GB归一化覆盖层。 2QF/伽马布在恒定H/ b下用Cu/ gammab和PO/γ线性增加，（2）两层土壤的轴承能力随H/ B的轴承增加，直到它成为均匀的无限沙子Layr的轴承能力。在无限沙子（H/b）**的轴承能力上均恒定的h/b的值约为1.5至2，圆滑的底层为4。（3）两者的故障机理地产土壤可以分为两类；一个是在沙里尔（H/b）**发生的沙雷中的一般faiure，另一个是在h/b下方的一块沙子的h/b下方，小于（h/b）**。（4）合并在恒定载荷下，这两个土壤随着其强度而增加。在H/B为1.0至2.0的地面上，施加的载荷强度与粉饰能力与固结定居点的比率之间发现了一个单一的关系。