轴对称解析解对马蹄形隧道衬砌水压力及渗透量适用性研究

Study of applicability of an axisymmetric solution for water pressure and seepage flow on lining of horseshoe shaped tunnel

为简化马蹄形隧道衬砌水压力及渗透量的计算方法,基于轴对称解析解与等效周长法,求得不同衬砌渗透系数、注浆半径和衬砌厚度的衬砌水压力与渗透量,并与FLAC3D数值模拟同等条件下相应工况的衬砌水压力与渗透量进行对比.研究表明:轴对称解析解简化马蹄形断面计算隧道衬砌水压力及渗透量的结果与数值模拟结果误差为7.7%,可以将其应用于工程中;3种工况下,最不利位置均位于拱腰;衬砌渗透系数减小与衬砌厚度增大,衬砌安全系数均在增大,而注浆半径的增大对衬砌安全系数无明显影响;衬砌渗透系数减小,衬砌水压力增大,渗透量减小,注浆半径增大与衬砌厚度增大,衬砌水压力与渗透量均减小.

In order to simplify calculating water pressure and seepage flow of a horseshoe shaped tunnel based on the axisymmetric solution and equivalent perimeter,the lining water pressures and seepage flows of different lining permeability coefficients,different grouting radii,different lining thicknesses are obtained;and then comparing them with corresponding lining water pressures and seepage flows of numerical simulation of FLAC3 Din the same circumstance.The study results show that the error between the results of the lining water pressure and seepage flow of the simplified horseshoe shaped tunnel in axisymmetric solution and the results of the lining water pressure and seepage flow of the numerical simulation is 7.7%;and it can be applied to the engineering.The study results also show that the most unfavourable position is at the hance of each conditions;that lining permeability coefficient decreasing and the lining thickness increases leads to that the lining safety factor increase;but grouting radius increases has no effect on the safety factor;the lining permeability coefficient decreases leads to that the lining water pressure increases and the seepage flow decreases;the grouting radius increasing and lining thickness increasing lead to the decreases of ining water pressure seepage flow.