单向压缩状态下饱和砂性土蠕变特性试验研究  

Creep of Saturated Sand under One-dimensional Compression

作　　者：王惠敏[1] 张云[1] 何佳佳[1] 

机构地区：[1]南京大学地球科学与工程学院,南京210093

出　　处：《地下空间与工程学报》2009年第A02期1580-1584,共5页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金项目(40772168);国家杰出青年科学基金(40725010)

摘　　要：为研究单向压缩状态下饱和砂性土的蠕变特性,本文进行了饱和砂性土在常规加载(即加载比为1)与加载比为3及等梯度加载等不同加载方式下的蠕变试验并对试验结果进行对比分析。结果表明:加载比不同时,3200kPa荷载下蠕变变形量基本相等;不同加载方式下,蠕变变形表现为与时间、荷载相关的非线性增长;将相邻荷载施加后同一时刻的蠕变增量定义为Δt,与常规加载试验中该参数随荷载量增加而不断增加相反,等梯度加载试验中Δt随荷载增大而减小并且逐渐趋于稳定,这是因为在等梯度加载试验中土体在每级荷载下都没有达到蠕变稳定,而且每级加载增量相对较小。Δt达到稳定时的荷载与加载梯度的对数呈线性关系。In order to study the creep properties of saturated sand, several tests with different loading patterns were conducted in this paper, including conventional loading （ loading ratio of 1 ）, loading with the loading ratio of 3, and equal gradient loading. The results indicate that the creep deformation is nearly the same for the loading of 3200kPa with different loading ratios, and that the creep deformation increases with time and load nonlinearly. The parameter A, is defined as the increment of creep deformation between two adjacent loading stages with the same elapsed time t, and the value of A, decreases and nearly reaches a constant with the increment of load in the equal gradient loading tests, while it increases with the load in the conventional loading test. The reason for this is that the creep deformation does not reach a stable state and the loading gradient is relatively smaller in each loading stage in the equal gradient loading tests. There is a linear relationship between the logarithmic loading gradient and the load at which A, is approximately a constant.

关 键 词：饱和砂性土 加载比 等梯度加载 蠕变变形 

分 类 号：TU411[建筑科学—岩土工程]