考虑渗透力的基坑水土压力计算

COMPUTATION OF WATER AND EARTH PRESSURES IN CONSIDERATION OF SEEPAGE

渗流不但决定了基坑支护结构上的水压力 ,而且所产生的渗透力也影响其上的土压力 ,以往对此认识不足。通过算例 ,对不同渗流工况下用不同计算方法进行比较分析。发现对于二维渗流情况 ,用朗肯土压力埋论计算不合理 ,与用库仑理论计算结果有较大差别 ;有上层滞水产生的水土压力不同于一般静水情况 ;当在基坑外采用真空井点降水时 ,会明显降低荷载 (主动土压力 ) ,增加抗力 (被动土压力 ) ,与在坑内排水比较 ,有助于基坑的稳定。

Seepage determines water pressure on supporting structure,and seepage force affects earth pressure on it before.But there is insufficient research in it before.Different seepage conditions and computation methods are compared and analyzed with examples here.It is indicated taht,when there is 2\|D seepage,results of Rankine's earth pressure theory is not reasonable,which is quite different from that of Coulomb's earth pressure theory;when there is superstratum perched water,water and earth pressure is different from that of static water;in comparison with dranage inside deep excavation,dewatering with well\|point outside can deduce active earth pressure and increase passive earth pressure,which helps to slope stabilization of deep excavation.