On the Timing of Secondary Lining Construction for Water Diversion Tunnels with Large Deformation in Soft Rock
In order to study the influence of different timing of secondary lining construction on the load bearing perform-ance of the lining structure,a simulation model of the deep-buried extra-long water diversion tunnels under complex geo-logical conditions is established based on three-dimensional finite element method,which can consider the excavation process and the initial support timing effect.The results show that the later the construction of the secondary lining,the more beneficial it is for the long-term safe and stable operation of the lining structure,theoretically.However,when the surrounding rock and the primary lining bear more than 90%of the excavation load,the plastic zone of the surrounding rock will be increased significantly if the steel support of the primary lining yields,which will affect the structural safety.If the secondary lining is constructed when the surrounding rock and the primary lining bear about 80%of the excavation load,the combined load bearing performance of the primary and the secondary linings can be better utilized.
soft rockwater diversion tunneltiming of secondary liningload bearing performancethree-dimensional finite element method
万方数据
维普
