袖阀管注浆技术改性土体研究及效果评价

注浆技术作为一种有效的岩土工程施工方法,理论研究远落后于工程应用。在简要分析袖阀管注浆原理及注浆机制类型的基础上,采用岩土颗粒流程序,从微观上模拟了单孔条件下不同注浆压力对土体改性效果的影响,认为随注浆压力的提高,土体出现显著的压密效应,拉应力增加且范围扩大,并产生劈裂注浆效应,尤其是注浆孔周围土体,空间置换率较大;同时模拟了多孔状态下浆液扩散、土体压密及劈裂效应产生的过程,认为对于土体改性存在一合理的注浆压力,浆液挤压土体并在土体中产生劈裂缝,在多孔之间贯通、交叉,形成网状浆脉,土体得到整体改性。模拟结果与现场注浆试验取得了较为一致的结果,土体改性效果良好。

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 theoretically proved to be a feasible method to reinforce soil masses.