透水衬砌理论在引黄工程出水高压管道设计中的应用

Application of Permeable Lining Theory in the Design of the High pressure Outlet Pipeline in the YRDP

引黄入晋工程总干线一、二级地下泵站出水高压管道，通过论证，岩石覆盖厚度满足要求，可以根据透水衬砌理论设计思想，以围岩做为内压主要承担者，采用钢筋混凝土衬砌设计，符合今后高压管道设计趋势。

The thickness of cover,the minimum principal stress,and the groutability of the surrounding rock around the high pressure outlet pipeline of the first stage and the second stage underground pumping stations on the General Main Line of the YRDP are tested respectively by the Norway criterion,the minimum principal stress criterion and the high head water pressure test.The test results show that the actual thickness of rock cover is more than 140m,which is greater than what is the required minimum as a thickness (120m),the ratio of the lateral minimum principal stress to the internal water pressure of the tunnel at all the measured points(>1.4)is bigger than that what is the required by the minimum principal stress criterion (1.05),and the Lugeon Value of most of the test segments is smaller than 1 Lu,only a few test segments,which are between 1Lu and 3 Lu,demonstrates the rock body around the high pressure outlet pipeline is of non groutability,but individual segments are of the poor groutability.The result illustrates that the permeable lining theory under a certain condition is applicable,namely,the common reinforced concrete lining might be used instead of the steel lining to save cost and time.However,it is necessary to take some engineering measures such as shotcreting,rock bolting,backfill grouting,contact grouting,high pressure consolidation grouting and so on according to demand.The antecedent experiment and observation during operating period have been emphasized for improving the theory itself.