考虑压滤效应饱和黏土压密注浆球孔扩张理论

Spherical cavity expansion theory of compaction grouting in saturated clay considering pressure filtration

摘要:

为了研究压滤效应对压密注浆的影响,在考虑滤出水渗流和土体弹性变形耦合的基础上,推导出了考虑压滤效应时饱和黏土压密注浆球孔扩张的控制方程．并在不考虑土体渗透率变化的前提下,对该控制方程进行简化,得到径向应力和径向位移的表达式,该简化方法可较好地计算球孔扩张问题中径向应力和径向位移．与本文计算方法相比,传统的球孔扩张理论无法考虑压滤效应和有效应力比的影响,当有效应力比较小时(即浆液较稀),传统方法的误差较大．利用本文方法对压密注浆过程进行分析,结果表明:随着半径的增大,径向应力显著减小,随着有效应力比的减小,内侧土体的径向应力逐渐减小;有效应力比对内侧土体径向位移的影响不大,而随着有效应力比的减小,周围土体的径向位移逐渐增大．

Abstract:

The control equation of spherical cavity expansion theory of compaction grouting in saturated clay considering pressure filtration was derived to study the effect of pressure filtration on compaction grouting. Then the control equation was simplified to obtain the radial stress and radial deformation by assuming constant soil permeability, and the radial stress and radial deformation could be well calculated by simplified method. Compared with the theory in this paper, the traditional spherical cavity expansion theory can not consider the impact of effective stress ratio and pressure filtration, so that the lower effective stress ratio will lead to larger error. The results show that, with the increase of radius, the radial stress decreases notably. With the decrease of effective stress ratio, the radial stress of inner soil decreases and the radial deformation of surrounding soil increases. However, the effective stress ratio has little influence on the radial deformation of inner soil.