应力释放率对水工隧洞衬砌开裂影响及其评价

Effect and Evaluation of Stress Release Rate of Surrounding Rock on Hydraulic Tunnel Lining Cracking

由于目前对于应力释放率对隧洞衬砌开裂影响及临界应力释放率评价缺乏系统研究,本文以水工隧洞K11+892.2~K12+012.2段为工程背景,运用弹塑性有限元分析应力释放率对隧道衬砌开裂影响程度,评价隧道衬砌开裂所对应的临界应力释放率。研究结果表明:隧洞横断面水平应力最大值与应力释放率大致呈非线性的负相关的关系,且随着应力释放率的增大而衬砌水平应力逐渐减小,并确定了临界应力释放率为61.5%,可有效确定衬砌的支护时机。本成果应用于水工隧洞施工不同阶段混凝土衬砌开裂风险评估,可有效指导水工隧洞建设的安全。

Due to the lack of systematic research on the impact of stress release rate on tunnel lining cracking and the evaluation of critical stress release rate,this paper takes the K11+892.2~K12+012.2 section of the hydraulic tunnel as the background and uses elastic-plastic finite element analysis to analyze the degree of influence of stress release rate on hydraulic tunnel lining cracking,evaluating the critical stress release rate corresponding to tunnel lining cracking.The research results indicate that the maximum horizontal stress in the cross-section of the tunnel is roughly in a nonlinear negative correlation relationship with the stress release rate,and gradually decreases with the increase of the stress release rate;In elastic-plastic model analysis,the critical stress release rate is determined to be 61.5%,by which the timing of lining support can be determined effectively.The results can be applied to the safety assessment of concrete lining cracking in different stages of hydraulic tunnel construction,and can effectively guide the safety of hydraulic tunnel construction.