具有衬砌的圆形水工隧洞弹塑性应力统一解

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

摘要:

针对具有衬砌的圆形水工隧洞，假定衬砌与围岩位移连续，考虑不同工况下主应力顺序、岩石应变软化和中间主应力等综合影响，采用统一强度理论和弹脆塑性软化模型，推导衬砌和围岩弹塑性应力统一解.选取不同的统一强度理论参数，可得到一系列应力场公式及塑性区半径与内压力的关系.通过工程算例分析知，考虑第一主应力的变化是正确的，更符合工程实际，并得出统一强度理论参数、软化特性参数对衬砌和围岩切向应力的影响规律.研究结果表明,统一强度理论参数和软化特性参数对衬砌与围岩塑性区切向应力的影响显著.

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.