基于流固耦合的水底隧道全断面注浆力学分析

全断面帷幕注浆加固围岩是水底隧道穿越断层破碎带、海底风化槽等高渗透性岩体常采用的辅助工法。帷幕注浆的主要目的是加固围岩,改善围岩的物理力学性质,降低围岩渗透系数。本文在对注浆加固机理及注浆参数选取研究的基础上,采用三维有限差分FLAC3D数值模拟手段,基于流固耦合的力学模型研究注浆加固圈厚度及渗透系数对围岩稳定性、渗流规律、支护结构受力的影响。研究结果表明:水底隧道洞室开挖对初始渗流场的改变程度及范围与注浆圈渗透系数有直接关系,通过有效注浆不但起到限排堵水的作用,还起到降低地下水渗透体积力、约束位移的作用。

Study on Whole Section Curtain Grouting Technique and Parameters Optimization in Subsea NATM Tunnel

The whole section curtain grouting technique is often used as a aided tunneling method to pass the fractured fault and the weathered rock-groove with high permeability in the subsea NATM tunnel.Through whole section curtain grouting,the mechanical behavior of the surrounding rock mass to be reinforced is improved and the permeability of the ground is lowered.The three-dimensional fluid-mechanical interaction model is given considering the coupled effects of the seepage field and geo-stress field based on the basic theory of seepage.Through comparison and analysis of the stresses and displacements of the subsea NATM tunnel with different parameters,the researches on the stability of ground,the law of permeability and the mechanical behavior of the support structure are achieved for subsea NATM tunnels.The results show the effective grouting decreases the ground water volume,lowers the magnitude of the seepage body force and plays the role of constraining displacements.