饱和填土Rankine被动土压力计算

从理论上分析了饱和填土分别处于无渗流和稳定渗流状态时Rankine被动土压力的计算问题。对填土面无超载的情况,当填土中存在稳定渗流时,挡墙仅受被动土压力作用,其大小取填土饱和重度计算;当饱和填土中无渗流时,挡墙同时受被动土压力和水压力作用,土压力取填土浮重度计算。对填土面作用均布荷载情况,当墙背为排水边界时,除荷载作用瞬间外,挡墙仅受被动土压力作用;当填土底面为排水边界时,只有当荷载在墙背引起的超静孔隙水应力完全消散后,挡墙才仅受被动土压力作用。在超静孔隙水应力完全消散前,挡墙同时受被动土压力和水压力作用,其大小和分布随固结度的不同而异;当填土中无渗流时,挡墙同时受被动土压力和水压力作用。

Rankine-Type Solutions for Passive Earth Pressure in Saturated Backfill

Some theoretical solutions for Rankine's passive earth pressure acting on retaining walls by saturated soil mass with/without steady water seepage are developed.Without load acting on the surface of the backfill,the wall is only acted by passive earth pressure in the case with steady water seepage;it is acted by both earth and water pressures in the case without water seepage.In the solution of the passive earth pressure in the case with water seepage,the saturated soil unit weight is used;but in the case without water seepage,the buoyant soil unit weight is used.With uniform load acting on the surface of the backfill,in the case with the water seepage through the backfill,the wall which is provided with a drainage system along the soil-structure interface is only acted by passive earth pressure except for the instant applying the load.And in the case with the water seepage and a drainage system along the backfill base,after the excess pore water pressure induced by the uniform load dissipated completely,the wall is only acted by passive earth pressure;before the excess pore water pressure is dissipated,the wall is acted by both earth and water pressures,but the magnitude and distribution of the earth and water pressures change with changing the degree of consolidation of the soil mass under the uniform load.And in the case without water seepage,the wall is also acted by both earth and water pressures.