FLAC^(3D)在青岛地铁渗流场中的应用

Application of FLAC^(3D) to seepage field of Qingdao metro

首先,基于考虑衬砌和注浆圈的解析解,利用MATLAB软件编制了计算与自动绘图程序,研究水头、隧道半径、围岩渗透特性与衬砌渗透系数和隧道涌水量、外水压力的相互关系;其次,基于FLAC3D软件平台,通过数值解与理论解的对比,验证了数值模拟方法在隧道渗流场中应用的正确性。在此基础上,结合青岛地铁典型区间隧道,分析了隧道开挖阶段以及运营期的渗流场,并研究了在不同注浆圈厚度以及注浆圈渗透系数下隧道注浆圈的涌水量和外水压力。结果表明,在隧道周围施作注浆圈的方法来减少隧道的涌水量是可行的。注浆圈厚度越大,其渗透系数越小,隧道涌水量就越小,而外水压力变化规律与涌水量恰恰相反。研究成果为地铁隧道衬砌的设计和注浆圈范围的初步确定提供了参考依据。

Firstly,based on considering the theoretical solution of liner and grouting circle,the calculation and automatic drawing program has been developed with MATLAB software;and the relationships among water inflow,external water pressure and water head,tunnel radius,rock permeability,lining permeability are researched.Secondly,through the comparison of the numerical result and theoretical solution based on the FLAC3D,the correctness of application of numerical simulation methods to the tunnel seepage field are verified.On this basis,combined with the typical range of Qingdao metro,the seepage fields in the excavation stage and operation period are studied;and the relationships between water inflow and external water pressure of grouting circle are researched under different grouting circle thickness and grouting parameters.The results show that the application of grouting circle to the tunnel to reduce the water inflow is feasible;and the greater the grouting circle thickness and the smaller the grouting circle permeability,the less the tunnel water inflow;but the changing law of the external water pressure is on the contrary.The obtained results play an important role in designing the liner and the preliminary definition of the grouting thickness.