考虑体积质量变化时非饱和土的土压力系数  

Expressions of coefficients of lateral earth pressure for unsaturated soils considering change of volume mass

作　　者：李顺群[1] 陈淮[2] 刘华新[1] 刘猛[1] 

机构地区：[1]辽宁工学院土木建筑系,辽宁锦州121001 [2]郑州大学土木工程学院,河南郑州450002

出　　处：《辽宁工程技术大学学报（自然科学版）》2006年第2期207-210,共4页Journal of Liaoning Technical University (Natural Science)

基　　金：辽宁省教育厅科学研究计划基金资助项目(2004F105)

摘　　要：利用非饱和土的双应力状态变量表示方法,各向同性和线弹性非饱和土的本构方程以及饱和度与基质吸力之间的关系,建立了非饱和土在考虑基质吸力和体积质量沿深度变化时的静止﹑主动和被动土压力系数表达式。通过数值积分求出了考虑不同因素作用时的三种土压力系数,并得到以下一些结论:非饱和土的土压力系数不仅与相应的饱和土参数有关,还与深度和基质吸力的分布有关;压力系数在较浅处一般较小,随深度的增加而增大,且三种系数均有在一定深度范围内为零即在地面产生裂缝的可能,主动情况下裂缝深度最大;基质吸力沿深度线性减小时的土压力系数最接近饱和时的土压力系数,且基质吸力减小的越快,两种压力系数越接近。Based on Fredlund＇s two stress state variable, relationship between matric suction and saturation degree for unsaturated soils is used to establish formulas considering change of matric suction and bulk weight along depth respectively for coefficients of earth pressure at rest, active and passive states. As an example, the three kinds of coefficients are calculated with different factors taken into account and some results are obtained. Firstly, there axe many parameters in the three formulas including not only those in corresponding formulas for saturated soils, but also distribution of matric suction along depth. Secondly, these coefficients will increase with depth and may be zero near ground, that is to say, cracks will occur. Thirdly, the coefficients are closest to those of saturated soils when matric suction linearly decreases along depth and the more decrescent, the closer the coefficients of unsaturated soils are to those of saturated soils.

关 键 词：非饱和土 土压力系数 基质吸力 有效饱和度 

分 类 号：TU432[建筑科学—岩土工程]