黄土山区贴坡填方地基的变形特性

Deformation characteristics of slope filling ground in loess mountainous areas

为了研究贴坡填方地基的变形特性,依托兰州市某黄土“削峁填沟”工程,开展贴坡填方地基沉降及水平位移监测,借助有限差分数值分析,研究了回填土压实度、坡面坡度、回填高度的影响.结果表明,贴坡填方地基沉降及水平位移均随着时间呈两段式增长,水平位移进入缓慢发展期的时间晚于沉降,原状土地基沉降在总沉降中占比大.竖向平面内沿水平方向,距离坡顶越近沉降越小、水平位移越大;沿深度方向,深度越深,沉降及水平位移均越小,土体深度方向水平运动不协同.压实度、坡度、高度对土体运动矢量长度、方向的影响效果不同,对变形控制的重要性依次为压实度>高度>坡度.实际工程应控制压实度>0.93,尽量减小坡度和一次性填筑高度.

To study the deformation characteristics of slope filling ground,a case of "cutting hills and filling valleys" in Lanzhou was taken as a basis.The field monitoring to settlement and horizontal displacement of slope filling ground was carried out.With the help of a finite difference numerical analysis,the influence of filling compactness,hillside slope and filling height was studied,and the results showed that the settlement and horizontal displacement of ground increased at two stages.The time of horizontal displacement entering into a slow development period was later than settlement,and the settlement of undisturbed soil had a large proportion in the total settlement.Along the horizontal direction on a vertical plane,the closer to the top of slope was,the smaller settlement and the larger horizontal displacement.Along the depth direction,the deeper depth was,the smaller settlement and horizontal displacement.The horizontal movement of soil in the depth direction was not coordinated.The influence of compactness,slope and height on the length and direction of soil motion vector was different,and the importance order of them to deformation control was compactness>height>slope.In practical engineering,the compactness should be controlled by more than 0.93,and the slope and filling height at one time should be reduced as much as possible.