考虑脆性损伤和渗流的圆形水工隧洞解析解

针对脆性岩石的损伤特性引入脆性损伤模型，导出三维各向同性损伤情况下的损伤变量表达式。在考虑损伤、不同工况主应力对应关系和渗流作用影响下，推导出圆形水工隧洞洞周围岩的弹塑性应力和塑性半径的解析解。对岩石的脆性特性的研究表明，考虑脆性损伤时的洞周围岩塑性半径比不考虑时有一定程度提升；围岩脆性特征越明显，塑性半径越大。无论洞周围岩应力状态如何，考虑渗流影响后，洞周围岩塑性区范围均会有所扩展。在内水压从0逐渐增加过程中，塑性半径随内水压增加而逐渐减小，直至塑性区消失，在超出临界内压后，塑性区重新出现，塑性半径逐渐增大。

Analytical solutions of circular hydraulic tunnel considering brittle damage and seepage

Considering the damage characteristic of the brittle rock,the brittle damage model is introduced;and the expression of damage variable under 3-dimension isotropic damage condition is derived.The analytical solutions of elastoplastic stress and plastic radius of the circular hydraulic tunnel are deduced,considering the seepage influence,damage influence and principal stress corresponding relations under different engineering conditions.The research about brittle characteristic shows that the plastic radius of surrounding rock will increase after considering brittle damage.The more distinct the brittle characteristic is,the more larger plastic radius will be.Whether the first principal stress of rock nearby the tunnel is radial stress or tangential stress,the consideration of seepage will expand the plastic zone of the surrounding rock.In the process of internal water pressure increase from zero,the plastic radius will gradually decrease accompany with the increase of internal water pressure,until the plastic zone disappears in the end;however,when the internal water pressure exceeds the critical pressure;the plastic zone appears again;the plastic zone will gradually increase.