Studies of sleeve-valve-pipe grouting technique and its effect on soil reinforcement

As an effective method of rock-soil reinforcement,the grouting technique has been widely used in civil engineering and well practiced;but the theoretical study is seldom concerned.In order to study the mechanism of soil reinforcement by pressure grouting,this paper,on the basis of brief analysis of the principle of sleeve-valve-grouting and grouting mechanism types,adopts a program of Particle Flow Code to simulate the effect of soil mass reinforcement under different grouting pressures in a single hole.With the increment of grouting pressures,the soil becomes denser;and with the increment of tensile stress in soil,the crack-induced grouting effect results,especially the special replacement ratio becomes great in soils surrounding the grouting hole.At the same time,the procedures of grouting slurry spreading,soil masses compacting and induced split grouting effect are also simulated.The results of simulation have also been verified by an in-situ grouting test.The technique of the sleeve-valve-pipe grouting has been theoreti-cally proved to be a feasible method to reinforce soil masses.