Research Initiation: Response of Saturated Silty Soils to Irregular Seismic Loads

研究启动：饱和粉质土对不规则地震荷载的响应

基本信息

批准号：
8808682
负责人：
Mladen Vucetic
金额：
$ 7万
依托单位：
University of California-Los Angeles
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1988
资助国家：
美国
起止时间：
1988-08-15 至 1991-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=8808682&HistoricalAwards=false
关键词：
Research Initiation Response Saturated Silty

项目摘要

Most of the populated regions of the world are concentrated in valleys, that is, on sedimentary deposits composed of different layers of cohesionless and cohesive soils, including nonplastic and plastic silts. The phenomenon of the amplification of ground motion in sedimentary deposits, as well as the loss of bearing capacity in all types of soils, and the liquefaction of saturated sandy or silty soils due to earthquake shaking, are only partially understood. The engineering properties if all soil materials (gravel, sand, silt, clay) under irregular seismic loads must be known in order to fully understand the above phenomena. This research project involves a laboratory investigation and analytical modelling of the response of saturated silty soils to irregular seismic loads. Loading conditions corresponding to the propagation of seismic waves will be simulated in the laboratory using cyclic direct simple shear and cyclic triaxial devices. Degradation of soil stiffness during cyclic loading, the associated variation of cyclic pore pressure, and the rules governing irregular cyclic stress-strain behavior are being investigated. The results obtained for silty soils are being compared to the corresponding available results on sands and clays. This comparison provides a basis for the development of mathematical models for the reduction in stiffness and the development of pore water pressure, valid for all three types of soils.

世界上大多数人口稠密的地区都集中在山谷中，即由不同层的无粘性和粘性土壤（包括非塑性和塑性淤泥）组成的沉积物上。对于沉积物中地震动放大的现象，以及所有类型土壤承载能力的丧失，以及由于地震震动导致饱和砂质或粉质土壤液化的现象，人们仅了解部分。为了充分理解上述现象，必须了解所有土壤材料（砾石、沙子、淤泥、粘土）在不规则地震荷载下的工程特性。该研究项目涉及饱和粉质土壤对不规则地震荷载响应的实验室调查和分析模型。与地震波传播相对应的载荷条件将在实验室中使用循环直接简单剪切和循环三轴装置进行模拟。正在研究循环加载过程中土壤刚度的退化、循环孔隙压力的相关变化以及控制不规则循环应力-应变行为的规则。将粉质土壤获得的结果与沙子和粘土的相应可用结果进行比较。这种比较为开发用于降低刚度和发展孔隙水压力的数学模型提供了基础，该模型对所有三种类型的土壤都有效。