超前灌浆参数设计及其加固防渗效果的数值分析

Numerical Analysis of Design of Pre-grouting Parameters and Effect of Reinforcement and Seepage Control

鉴于地下水丰富且地质条件复杂洞段采用超前灌浆技术是解决涌水突砂和加固围岩效果较好的工程措施。选取滇中引水隧洞高埋深、高水头、Ⅳ类围岩段为例,采用数值分析的方法探讨了超前灌浆深度的合理化选取,并对比分析了有无超前灌浆下洞周围岩的加固和防渗效果。结果表明,与无超前灌浆相比,在合理的灌浆深度下洞周围岩的变形量和破坏深度及隧洞的渗水量均明显减小,超前灌浆达到了加固围岩和防渗的双重效果,为实际施工中遇到类似问题提供了切实可行的建议。

In view of the abundant groundwater and complex geological conditions of the tunnel,pre-grouting technology is one of the good engineering measures to solve sudden gushing sand and reinforce rock mass.This paper takes Yunnan diversion tunnel with high buried depth,high water head and IV surrounding rock as an example,and explores the reasonable selection of pre-grouting depth by using the numerical analysis method and compares the reinforcement and anti-seepage effect of the surrounding rock in the conditions of with and without pre-grouting.Compared with no pre-grouting,the results show that the deformation and failure depth of the surrounding rock and the quantity of water flow of the tunnel are reduced significantly under a reasonable grouting depth.Pre-grouting achieves a double effect of surrounding rock reinforcement and seepage control,which provides practical suggestions for the construction of similar actual projects.