Study on the substantial increase in the seismic stability of reinforced soil structures by preloading and prestressing

预压和预应力大幅提高加筋土结构抗震稳定性的研究

基本信息

批准号：
09555149
负责人：
TATSUOKA Fumio
金额：
$ 7.04万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09555149/
关键词：
Reinforced soil structures Seismic stability preloading and prestressing Model loading tests Shaking table tests Granular material Geotextile High seismic load ジオテキスタイル補強土交通荷重地震荷重原位置測定

项目摘要

The basic mechanism of substantial increasing the seismic stability of reinforced soil structures by preloading and prestressing was studied by performing static cyclic loading tests and shaking table tests on small-scaled models of pier structures. Based on the proposal of the researchers, a prototype bridge pier for a railway bridge of geotextile-reinforced gravel has already been constructed near the Hakata station in Kyushu three years ago. The gravel backfill of the structure that was reinforced with a number of horizontal geotextile layers was preloaded in the vertical direction before having been fixed to prestressed conditions. The model test results showed that reinforced structures become very strong under seismic loading conditions as far as a sufficiently large prestress was maintained. When the input seismic load was a long period of uniform sinusoidal waves with an amplitude of 700 gals at a frequency that was nearly the same with the natural frequency of the structure, the nearly-resonance response at the top of the structure was as high as 2,000 gals. Even in that case, the structure exhibited only a limited amount of cyclic lateral displacement with some residual vertical compression. A method for maintaining prestress when the structure is exhibiting settlement was examined and found effective and practical. Geotechnical analysis of the test results was made for developing the design method.

通过对桥墩结构小型模型进行静力循环加载试验和振动台试验，研究了预压和预应力大幅提高加筋土结构抗震稳定性的基本机理。根据研究人员的建议，三年前，九州博多车站附近已经建造了土工布加固砾石铁路桥原型桥墩。结构的砾石回填物由多个水平土工织物层加固，在固定到预应力条件之前在垂直方向预载。模型试验结果表明，只要保持足够大的预应力，加固结构在地震荷载条件下就会变得非常坚固。当输入地震荷载为振幅为700加仑、频率与结构固有频率几乎相同的长周期均匀正弦波时，结构顶部的近共振响应高达2,000加仑。即使在这种情况下，结构也仅表现出有限的循环横向位移和一些残余垂直压缩。对结构出现沉降时保持预应力的方法进行了检查，结果发现该方法有效且实用。对测试结果进行岩土分析以开发设计方法。