任意埋深水下隧道渗流场解析解

Analytical solutions for seepage fields of underwater tunnels with arbitrary burial depth

总结现有关于水下隧道渗流场解析研究的优点和不足,基于稳态渗流控制方程,结合保角变换方法,严格推导了水下隧道渗流场的解析解。该解能求解任意埋深考虑注浆圈作用的水下衬砌隧道渗流量以及水压力分布,并能退化到无衬砌水下隧道以及水下不透水管道两种极端情况,应用Comsol软件建立数值模型验证了新解答的正确性。利用本文解研究了隧道埋深、衬砌渗透系数、衬砌厚度等因素对隧道渗流量、衬砌外水压以及总水头分布的影响。研究发现当隧道埋深较小时,最大水压力出现在隧道顶部,而埋深较大时,则出现在隧道底部;衬砌外圈平均水压力及分布不均匀程度随着埋深的逐渐增大先减小后增加;其他参数不变时,存在某个埋深或者衬砌厚度使衬砌外水压力接近均布。

A summary about the analytical solutions in the literatures for the seepage fields of underwater tunnels is given,whose advantages and disadvantages are pointed out.Based on the governing equation for the steady-state seepage,the analytical solutions for the seepage fields of underwater tunnels are derived rigorously using the conformal mapping method.The water inflow and water pressure distribution for the grouted lined underwater tunnel with arbitrary burial depth can be obtained according to the new solutions.The analytical solutions can be degenerated to two limit cases including the unlined underwater tunnel and the underwater pipeline.A numerical model is established using the software Comsol to validate the newly derived solutions.The effects of the burial depth of tunnel,the permeability of lining and the thickness of lining on the water inflow,the pore water pressure around the lining and the distribution of the total water head are investigated.It is found that the maximum water pressure appears at the top of the lining when the tunnel is buried shallowly,which is opposite for the case with a large burial depth.The average pore pressure and the non-uniform degree of distribution of the pore water pressure around the lining decrease first then increase as the burial depth increases gradually.And for a given working condition,there is a burial depth or thickness of lining,which can make the pore water pressure around the lining distributed uniformly.