砾石心墙土复杂应力耦合作用下的渗流特性  

Permeability of gravel soil for core wall under complex stress coupling effect

作　　者：詹美礼[1] 辛圆心 唐健[1] 黄青富[2] 盛金昌[1] 罗玉龙[1] 

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]昆明勘测设计研究院,云南昆明650000

出　　处：《水利水电科技进展》2016年第4期36-41,共6页Advances in Science and Technology of Water Resources

基　　金：国家自然科学基金(51474204;51579078)

摘　　要：为研究土石坝中心墙土在复杂应力状态下的渗透特性以及其渗透性演变模型,利用自行研制的渗流-应力耦合试验装置,针对长河坝水电站砾石土进行多种应力耦合作用下渗透特性试验研究。结果表明:复杂应力状态对心墙土渗流特性影响显著;土样在设计水力梯度内渗流满足达西定律,且均未发生渗透破坏;在同一围压下,砾石土体的渗透系数随着偏应力和轴向应力的增大而逐渐减小;试验过程中轴向应变随应力作用时间的变化呈阶梯状,且随着偏应力的增大,渗透梯度和轴向应变也增大;建立了土体渗透系数与应力函数的经验公式,从理论上进一步揭示了砾石心墙土应力耦合作用下的渗透机制。In order to study the permeability characteristics and permeability evolution model of gravel soil used in core wall of earth-rock dam, a self-made seepage-stress apparatus was used to conduct permeability test for gravel soil of the Changheba Hydropower Station in complex stress state. Test results show that complex stress has significant effect on permeability evolution of gravel soil, the relationship between seepage velocity and hydraulic gradient follows Darcy’ s law within the range of the design hydraulic gradient, and seepage failure of soil samples does not occur. The results also show that under the same confining pressure, permeability coefficient of gravel soil decreases gradually as the partial stress and axial stress increases. There is a stepwise relationship between the axial strain and the stress acting time in the test process. As the partial stress grows, the axial strain increases with the seepage gradient. An empirical formula for relationship between the permeability coefficient and the stress function is established, which further reveals the permeability evolution mechanism of gravel soil under complex stress theoretically.

关 键 词：砾石心墙土 复杂应力 渗透系数 轴向应变 渗透性演变 

分 类 号：TV139.16[水利工程—水力学及河流动力学]