基于FLAC^(3D)分析的巷道“固帮顶控底鼓”支护方案

Supporting Program of “Strengthening Roof and Sides to Control Floor Heave” for Tunnel based on FLAC^(3D) Analysis

甘肃魏家地煤矿二号石门受到构造应力和采动应力影响,从而产生破坏,具体表现为顶板下沉量大,两帮位移大,底鼓严重。经过多次返修支护,变形破坏现象严重,已经影响到安全生产。根据地质分析情况和以往支护返修情况,结合查阅已有的相关资料,使用FLAC3D数值模拟软件建立模型,对提出的通过加固巷道顶板和两帮从而减小底板底鼓的方案安全性进行了计算。计算结果表明,采用该方案进行支护后,巷道的帮部和顶部变形以及底鼓现象均得到了有效控制。现场监测结果表明:特别是对于软弱围岩巷道来讲,通过加强帮部和顶部的支护强度,可以在一定程度上间接控制巷道的底鼓现象。该支护方案合理可行,满足了该巷道的安全。

The tunnel named 2#cross-hole of Weijiadi coal mine in Gansu province influenced by both of tectonic stress and mining-induced stress is damaged,which shows as large roof subsidence,huge two-side wall displacement and serious floor heave.After repairing for many times,the damaged support has influenced the production and the safety.By the numerical simulation software FLAC^3D,based on the analysis of the geological condition and the previous repairing supporting and referring to the pre-existing relative information,one model of the supporting program is built to calculate the safety of the supporting program that is to control floor heave by strengthening roof and sides of the tunnel.The calculation results indicate that the deformation of roof and sides and the floor heave are controlled effectively with the supporting program.The field monitoring results showed that for the soft rock tunnel,the supporting program of strengthening the intensity of roof and sides of the tunnel can control the floor heave in some way.This supporting program is reasonable and feasible,and can meet the requirement of the tunnel safety.