一维稳态流下非饱和土静止土压力系数的铅直分布  

The vertical distribution of coefficient of earth pressure at rest under one dimentional steady flow

作　　者：陈茜[1] 程大伟[2] 郭光玲[1] 

机构地区：[1]陕西理工大学土木工程与建筑学院,陕西汉中723001 [2]长安大学环境科学与工程学院,西安710000

出　　处：《中国科技论文》2017年第1期95-100,共6页China Sciencepaper

基　　金：中央高校基本科研业务费基础研究计划项目(310829151076)

摘　　要：对一维稳态流下非饱和土静止土压力系数铅直分布开展研究,根据非饱和土上覆应力微分方程,推导一维稳态流条件下土的重度和上覆应力铅直分布表达式,并基于此对非饱和土静止土压力系数铅直分布表达式进行修正。研究结果表明:重度的铅直分布函数近似呈幂函数;上覆应力的铅直分布函数为一线性函数和一定积分函数的叠加;修正后静止土压力系数表明该系数除了受土的物理性质影响之外,还与流动条件有关。最后通过算例计算和分析在不同流动方向和比流量情况下均质非饱和黄土层内土的重度、上覆应力和静止土压力系数的铅直分布。算例的结果表明:非饱和黄土层内土的重度铅直分布规律对流动方向和比流量的变化敏感,土的重度在入渗条件下最大,静水条件下次之,蒸发条件下最小;入渗条件下土的重度随比流量的增大而增大;蒸发条件下,则相反;上覆应力沿铅直方向近似呈线性分布;静止土压力系数在入渗条件最大,静水条件次之,蒸发条件最小;入渗条件下静止土压力系数随比流量的增大而增大;蒸发条件下,则相反。The coefficient of earth pressure,which reveals the relationship between horizontal stress and vertical stress of soil in any deepth under unconfined deformation conditions,is one of the most important coefficients in rock and soil mechanics.The vertical distribution of the coefficient of earth pressure at rest for unsaturated soil under one dimensional steady flow was evaluated in this paper.Based on the differential equation of overlying stress,the expression of gravity density and overlying stress are obtained.By those expressions,the corrected expressions of the vertical distribution of coefficient of earth pressure for unsaturated soil were obtained.The research showed that the gravity density vertical distribution closely followed the power function.The vertical distribution of overlying stress is the summation of a linear function and a definite integral function.The corrected expressions of the coefficient of earth pressure were affected by both soil physical property and flow condition.In addition,gravity density,overlying stress and the coefficient of earth pressure vertical distribution in unsaturated loess were calculated and analyzed under different flow direction and specific discharge conditions.The results showed that the law of vertical distribution for the gravity density was sensitive to flow direction and specific discharge change.The gravity density reached the maximum value was under infiltration conditions,which was followed by hydrostatic conditions.It reached the minimum under evaporation conditions.Under infiltration conditions,the gravity density increased with the increase of specific discharge.Under evaporation conditions,the conclusionwas opposite.The overlying stress followed the linear distribution in vertical direction.The coefficient of earth pressure reached the maximum value under infiltration conditions,which was followed bythe hydrostatic conditions.The minimum value was reached under evaporation conditions.Under infiltration conditions,the coefficient of earth pressure incre

关 键 词：一维稳态流 重度 上覆应力 静止土压力系数 铅直分布 

分 类 号：TU432[建筑科学—岩土工程]