防排水系统对复合式衬砌渗透特性的影响及表征方法

Effect of Waterproof and Drainage System on Seepage Properties of Composite Lining and Its Characterization Method

摘要:

采用修正的初衬渗透系数表征复合式衬砌的渗透特性。建立了复合式衬砌渗流模型，推导了复合式衬砌的渗透系数计算公式，并分别采用模型退化方法和数值法对提出的公式进行了验证。结果表明：当围岩渗透系数为1×10^-7~1×10^-6 m·s^-1时，考虑环向排水管、土工布和防水板的复合式衬砌渗透系数对涌水量和外水压力的影响不容忽视；复合式衬砌渗透系数与环向排水管间距、初衬渗透系数、初衬内外半径、土工布厚度、土工布渗透系数密切相关；环向排水管间距越大，复合式衬砌渗透系数越小。

Abstract:

The corrected initial lining permeability coefficient is adopted to characterize the permeability of composite lining. A seepage model of composite lining is established and the correction formula of the permeability coefficient of composite lining is derived. Then， the proposed formula is verified by using the model reduced and numerical method. It is found that： when the rock surrounding permeability coefficient in the range of 1×10^-7??1×10^-6 m·s^-1， with a consideration of drainage pipes， geotextile and waterproof sheet， the effect of the permeability coefficient of composite lining on water inflow and external water pressure should not be ignored； the permeability coefficient of composite lining is closely related to the distance between two circular drainage pipes， the permeability coefficient of initial lining， the inner and outer radius of initial lining， the thickness and the permeability coefficient of geotextile； the larger the distance between two circular drainage pipes， the smaller the permeability coefficient of composite lining.