Elastic-plastic Stress Unified Solutions of a Circular Hydraulic Tunnel with Lining

Abstract:

The displacement between surrounding rock and lining assumed to be the consecutive,the elastic-plastic stress unified solutions of a circular hydraulic tunnel with lining are obtained based on unified strength theory and elastic-brittle-plastic softening model by taking into consideration the effects of principal stress orders in different engineering conditions,rock strain softening,and the intermediate principal stress.A series of stress fields and the plastic radius versus inner pressures are obtained by choosing different unified strength theory parameters.A case study shows that the obtained result is more accurate and closer to the practical engineering if taking the different maximal principal stress into account.The influence laws of the unified strength theory parameters and strain softening characteristic parameters on the tunnel tangential stress are discussed. The results show that tangential stresses of lining and surrounding rock in the plastic zone are significantly influenced by the unified strength theory parameters and strain softening characteristic parameters.