饱和原状黄土液化基本特征的振动台试验研究

发布时间：2018-01-16 18:25

本文关键词：饱和原状黄土液化基本特征的振动台试验研究　出处：《地震工程学报》2015年04期 　论文类型：期刊论文

【摘要】：天然黄土因其较强的结构性,制备大尺寸原状试体非常困难,国内外尚无针对饱和原状黄土实施振动台模拟试验的数据与资料。通过解决大尺寸原状黄土试体现场取备难题,利用振动台模拟试验研究饱和原状黄土液化现象及其基本特征。试验结果表明:饱和原状黄土的液化现象,在超孔隙水压力增长、持续与消散的趋势性上与饱和砂土具有可比性,二者的最大差别在于细节特征方面的不同;饱和度是决定地震作用下天然黄土液化特性的首要条件;试体饱和度约为90.3%的条件下,加载后的最大孔压比约为0.93;饱和度85%、75%和65%可能是天然黄土能否发生液化现象、似液化现象(循环失效)和不考虑循环失效现象的临界值。试验获得的资料与分析结果,对深入理解饱和土体液化物理过程与力学机制意义重大。
[Abstract]:Because of its strong structural properties, it is very difficult to prepare large scale undisturbed samples of natural loess. There is no data and data of shaking table simulation test for saturated undisturbed loess at home and abroad. The liquefaction phenomenon and its basic characteristics of saturated undisturbed loess are studied by shaking table simulation test. The experimental results show that the liquefaction of saturated undisturbed loess increases in excess pore water pressure. The trend of persistence and dissipation is comparable to that of saturated sand, and the biggest difference between them lies in the differences in details. Saturation is the primary condition for determining the liquefaction characteristics of natural loess under earthquake action. When the saturation is about 90.3%, the maximum pore pressure ratio after loading is about 0.93; The saturation of 85% and 65% may be the critical values of natural loess liquefaction phenomenon, similar liquefaction phenomenon (cyclic failure) and failure phenomenon without considering the cyclic failure phenomenon. It is of great significance to understand the physical process and mechanical mechanism of saturated soil liquefaction.
【作者单位】：中国地震局黄土地震工程重点实验室;中国地震局兰州地震研究所;兰州大学土木工程与力学学院;
【基金】：国家自然科学基金项目(50978239;51209186) 中国地震局地震预测研究所基本科研业务费项目(2013IESLZ01)
【分类号】：TU444
【正文快照】： 0引言天然黄土在工程地质与力学性质方面表现出的独特性[1],与土体具有的多孔隙、弱胶结的结构特征密切关联[2-3]。地震作用下的饱和黄土液化现象的基本特征,也必然受土体具有的上述结构特性的控制。天然黄土因地区、埋深不同存在明显的差异性,饱和黄土液化过程及其所表现出的

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