Mechanical property testing and back analysis of load models of metro shield tunnel lining in loess strata
Based on the Xi'an metro shield tunnel traversing old loess strata, dynamic tracking measurements of water pressure, earth pressure and structure internal force (axial force and bending moment) are carried out to analyze influences of the shield tail serum injection, cylinder thrust force, soil stress relaxation and water pressure on the distributions and varying laws of segment ring.Combining with field test data of internal force, the distribution mode and value of the load pressure on the segment lining in old loess strata are back analyzed by using orthogonal design method and defining target function.Internal force which are calculated by using optimized design parameters are quite close to measured value in magnitude and distribution.The results show that the analysis method proposed is feasible and reasonable; so it can be used for reference of similar projects.