超前全断面与半断面帷幕注浆效果分析

Effect Analysis of Curtain Grouting in Full-section and Half-section in Advance

针对在建公路隧道穿越断层破碎带时安全的施工方法,采用数值模拟结合现场监控量测的方法,对比分析了未进行注浆加固、超前半断面帷幕注浆和全断面帷幕注浆3种工况下初期支护的受力变形特性,评价了不同工况下的注浆效果。分析结果表明:未进行注浆加固工况下的拱顶沉降、仰拱隆起和周边收敛分别是超前半断面及全断面帷幕注浆的2.41倍、1.18倍、11.08倍和2.87倍、3.69倍、14.72倍;超前全断面帷幕注浆工况下的初期支护最大拉应力、最大压应力为4.24 MPa和26.85 MPa,比未进行注浆加固和超前半断面帷幕注浆减少了271.93%、363.21%和15.83%、28.57%。沉降监测数据非线性回归分析结果表明超前半断面、全断面帷幕注浆两种工况下沉降均趋于收敛,表现出安全稳定态势。

In this paper,according to the safe construction method when the highway tunnel under construction passes through the fault fracture zone,the stress and deformation characteristics of the initial support under three working conditions of without grouting reinforcement,advanced half section curtain grouting and full section curtain grouting are compared and analyzed,and the grouting effect under different working conditions is evaluated.The results show that the settlement of the arch crown,the uplift of the inverted arch and the convergence of the surrounding area are 2.41 times,1.18 times,11.08 times and 2.87 times,3.69 times and 14.72 times of the curtain grouting of the half section and the full section respectively,and the maximum tensile stress and the maximum compressive stress of the initial support are 4.24 MPa and 26.85 MPa under the condition of the curtain grouting of the full section,which are higher than those without the grouting and reinforcement The curtain grouting of the first half section decreases by 271.93%,363.21%and 15.83%,28.57%.The results of nonlinear regression analysis of settlement monitoring data show that the settlement tends to converge under the conditions of half section and full section curtain grouting,showing a safe and stable situation.