南水北调西线工程深埋长隧洞管片衬砌结构受力分析

NUMERICAL ANALYSIS OF SEGMENT LININGS IN DEEP AND LONG TUNNELS OF WEST ROUTE OF SOUTH-TO-NORTH WATER TRANSFER PROJECT

地应力和地下水问题对深埋长隧洞衬砌的设计及施工具有重大影响。通过数值计算对南水北调西线工程深埋长隧洞管片衬砌结构进行了受力分析,研究了围岩变形及水压力对管片衬砌结构的影响。初步研究结果表明:约90%的洞段稳定性较好,围岩变形对管片衬砌结构影响较小,可采用管片衬砌;隧洞沿线外水压力较高,是影响衬砌设计的主要因素,应采取适当的排、堵措施降低外水压力对管片衬砌结构的作用。研究结果为南水北调西线一期工程隧洞衬砌设计提供了依据。

In-situ stress and groundwater have important influences upon the design and construction of the lining for deep and long tunnels. The mechanical properties of segment linings for deep and long tunnels of west route of South-to-North Water Transfer Project are analyzed by using numerical simulation method. The influence of surrounding rock deformation and water pressure on the segment linings is studied. The preliminary results show that the segment linings can be used in approximate 90% segment of the tunnel as the surrounding rock has a good stability and the deformation has less influence upon segment linings. The external water pressure is very high around the tunnel, which is the main factor affecting the design of tunnel lining. The measures of high-pressure concrete grouting should be applied to decrease the external water pressure. The results can provide a basis for the design of linings in the first phase of the west route of South-to-North Water Transfer Project.