深埋岩溶隧道掌子面突水灾害可靠性上限分析OA北大核心CSTPCD

The study aims to analyze the reliability of water inrush disaster prevention at faces in deep-ly buried karst tunnels under high ground stress,high-pressure and water-rich conditions.Built upon existing research and the geological environment,a 3D outburst prevention mechanism for the tunnel faces,primarily based on shear failure,was constructed using the upper bound analysis method.An energy equation for the water inrush failure process was established based on the principle of virtual work rate.The Hoek-Brown strength criterion was used to determine the upper limit solution for the support pressure required to prevent water inrush in tunnel faces under high ground stress,high-pres-sure,and water-rich conditions.Under the state of extreme failure,a limit state equation was estab-lished based on the support pressure applied to the tunnel faces and the surrounding rock pressure at the time of water inrush failure.A reliability model for outburst prevention at the faces of deeply buried karst tunnels was established.To determine the likelihood of water inrush disasters at tunnel faces,the response surface method(RSM)was applied.The effects of horizontal ground stress,water pres-sure in dissolution cavities,rock mass strength parameters,and tunnel diameter on support pressure and potential failure length were analyzed.The minimum support pressure required to prevent water inrush disasters in deeply buried karst tunnels under different allowable failure probabilities and the maximum damage length that could be resisted under limited support effectiveness was provided.Ap-plied to practical engineering cases and compared with existing studies and field results,the findings confirm the effectiveness of the calculated results,offering theoretical guidance for preventing outburst problems in similar deeply buried karst tunnels in the future.