隧道尺度对衬砌背后水压力的影响机理研究

Study on influence mechanism of tunnel scale on water pressure behind lining

为了明确高水压围岩隧道的隧道半径、复合衬砌厚度以及围岩、注浆加固圈、衬砌渗透系数的相互关系对隧道衬砌背后水压力的影响,本文利用渗流连续性方程与达西定律得到了衬砌背后水压力计算方法。通过分析发现:隧道尺度较小时,隧道半径增大可显著减小衬砌背后水压力;注浆层厚度的增大,增加了渗流路径长度,降低了衬砌背后水压力;随着复合衬砌厚度的增加,衬砌背后水压力逐渐增加,衬砌厚度小于0.8 m时,衬砌厚度对衬砌背后水压力影响较大。本文的计算方法以及分析结果可以为高水压下隧道的衬砌支护设计参数、围岩加固设计参数提供理论参考。

In order to clarify the influence of the tunnel radius,composite lining thickness and the interrelationship of the surrounding rock,grouting reinforcement circle and lining permeability coefficient on the water pressure behind the tunnel lining of high-hydrostatic surrounding rock,the calculation method of the water pressure behind the lining is obtained by using the seepage continuity equation and Darcy's law.The main conclusions are as follows:(1)When the tunnel size is small,the increase of tunnel radius can significantly reduce the water pressure behind the lining;(2)The thickness of the grouting layer increases the length of the seepage path,increases the seepage resistance,and reduces the the water pressure behind the lining;(3)As the thickness of the composite lining increases,the water pressure behind the lining gradually increases.When the thickness of the lining is less than 0.8m,the thickness of the lining has a great influence on the water pressure behind the lining.The calculation methods and analysis results proposed in this paper can provide theoretical references for the design parameters of lining support and surrounding rock reinforcement of tunnels under high water pressure.