摘要
利用GDS三轴测试系统,对原状黄土进行了等压/偏压固结不排水剪(ICU/ACU)、常剪应力排水剪(CQD)试验。ICU和ACU试验表明:土体的应力-应变模式为强烈应变软化型,得到了其稳态线和潜在不稳定区,提出液化发生的必要条件就是土体状态位于或被带到潜在不稳定区域内。CQD试验表明,土体破坏的启动摩擦角远小于稳态摩擦角。当其应力路径试图穿越不稳定区时发生不完全排水剪缩破坏,具有突发性,检验了提出的不稳定区域的有效性。基于潜在不稳定区域的位置和斜坡土体的应力状态,提出了饱和黄土静态液化分析方法。
A series of triaxial compression tests, composed of isotropically and anisotropically consolidated undrained compression （ICU and ACU） tests and constant shear drained compression （CQD） tests, are carded out on undisturbed saturated loess by GDS apparatus. The results of ICU and ACU tests performed at the in-situ stress level show that the soils are of consistently strain-softening in the stress-strain relations. The steady-state line and the potential region of instability are obtained from ICU and ACU test results. A necessary condition for liquefaction is that the soil state initially lies in or is brought into the potential instability region; CQD tests demonstrate that the mobilized friction angle is far less than the steady-state angle and that the soil experiences undrained contractive failure suddenly at very small strains when its stress path during drained loading tries to cross the potential instability region; thus the proposed instability region is validated. Based on the location of the region of potential instability and the stress state of slope soil, a method of static liquefaction analysis is proposed for loess landslides caused by rise in groundwater table.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2008年第12期3293-3298,共6页
Rock and Soil Mechanics
基金
香港研究资助局(No.RGC-HKU7176/05E)
关键词
稳态线
不稳定区
应力路径
静态液化
steady-state line
potential instability region
stress path
static liquefaction
