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PREDICTION OF DEFORMATION OF GROUND LIQUEFIED DUE TO EARTHQUAKE

地震液化地面变形预测

基本信息

批准号：
10650478
负责人：
YOSHIMINE Mitsutoshi
金额：
$ 2.56万
依托单位：
TOKYO METOROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650478/
关键词：
liquefaction of ground flow deformation of ground laboratory soil testing anisotropy dilatancy initial shear triaxial test hollow cylinder torsional test ダイレタンシー

项目摘要

(1) Modifications of apparatus: First, existing triaxial apparatus was modified for accurate and smooth cyclic loading test. To conduct large deformation test, new pedestal and cap facilitated with end-friction free mechanism were also manufactured. Second, pressure system and measurement-control system of the existing hollow cylinder torsional apparatus was renewed. Torsional shear driving system was also manufactured so that simultaneous monotonic and cyclic loading with large deformation. Further more, pedestal and cap of the torsional apparatus were modified for larger specimen.(2) Developing of measurement system: Personal computer programs were developed for the experiments. This program enabled real-time display of external forces on the specimen and stress and strain components of the specimen. It also enabled fast-speed sampling of the measurements. The feature of this program is the calibration system that directly related the strain of the gauges on the sensors and the outpu … More t of AD converter.(3) Triaxial tests: First, a series of undrained monotonic loading tests were conducted on sand and the effect of loading direction (i.e. triaxial compression vs. extension) was examined. Especially, the effects of initial shear loading was studied with attention to the anisotropy of the specimen. Second, numerous undrained cyclic tests were conducted and the strength of sand to liquefaction with initial shear stress conditions were closely examined. From these test results, it was concluded that the triaxial compression in initial shear and subsequent undrained shear deformation, those are the common testing procedure for liquefaction tests for sand, overestimate the resistance of sand deposit to liquefaction failure.(4) Hollow cylinder torsional shear tests: In the view point of the importance of the anisotropic nature of sand, undrained shear tests in genera stress and strain conditions such as simple shear tests were conducted. It was found that the undrained behavior of sand in simple shear was the intermediate of those from triaxial compression and extension the test results indicated that it was possible to estimate the undrained shear deformation in general stress and strain conditions from triaxial compression and extension tests. In addition to these laboratory tests, case study from past failures in fields was conducted and it was shown that the laboratory test results in simple shear condition were well consistent with the field observations. Less

(1)仪器改造：首先，对现有三轴仪进行改造，使循环加载试验准确、平稳。为了进行大变形试验，还制造了便于端部无摩擦机构的新底座和盖。其次，对现有的空心圆柱扭转仪的压力系统和测控系统进行了改造。设计了扭剪驱动系统，实现了大变形单调加载和循环加载的同时进行。此外，还对扭转仪的底座和顶盖进行了改进，以适应较大的试件。(2)测量系统的开发：编制了实验用的微机程序。该程序可实时显示试样上的外力以及试样的应力和应变分量。它还支持测量的快速采样。该程序的特点是校准系统直接关联传感器上应变片的应变和输出。 ...更多信息测试AD转换器。(3)三轴试验：首先，对砂土进行了一系列不排水单调加载试验，并研究了加载方向（即三轴压缩与拉伸）的影响。特别是，初始剪切载荷的影响进行了研究，注意到试样的各向异性。其次，进行了大量的不排水循环试验，并仔细检查了初始剪应力条件下砂土的液化强度。从这些试验结果可以得出结论，三轴压缩在初始剪切和随后的不排水剪切变形，这些是常见的测试程序的砂土液化试验，高估了阻力的砂土存款液化破坏。(4)空心圆柱扭剪试验：考虑到砂土各向异性的重要性，进行了一般应力应变条件下的不排水剪切试验，如简单剪切试验。试验结果表明，砂土的单剪不排水特性介于三轴压缩和三轴拉伸的不排水特性之间，用三轴压缩和三轴拉伸试验来估算一般应力应变条件下的不排水剪切变形是可能的。除了这些室内试验，案例研究，从过去的故障在现场进行，它表明，在简单的剪切条件下的室内试验结果与现场观察是一致的。少