深埋引水隧洞安全监测数据分析

Analysis on Safety Monitoring Data of Deep Diversion Tunnels

安全监测在地下引水隧洞工程施工过程中发挥着重要作用,监测数据可真实反映开挖施工过程中围岩变形过程和应力变化情况。东疆调水工程KSVII标地下隧洞埋深超深,开挖过程中施工支洞与上游主平洞、下游主平洞相互交叉,且交叉段洞室跨度较大,地质条件差,围岩应力结构复杂。为了分析调水工程深埋引水隧洞围岩变形、应力分布规律和发展特征,通过安装埋设监测仪器及时获取安全监测数据资料,在监测数据资料分析的基础上,分析围岩变形和应力变化情况,结果表明:围岩位移变形与围岩内部应力变化趋势基本吻合,监测仪器数值受开挖施工影响,围岩应力释放,围岩结构发生蠕变影响仪器测值变化速率持续增加;随着洞室全断面开挖完成,围岩应力重新调整,逐步向临空面释放,导致后续监测过程中监测值出现不同程度的增加或波动,待围岩应力调整完成后,监测值逐渐趋于稳定;开挖施工过程中应减少对围岩的扰动,同时及时支护,以便保障工程施工安全。研究成果可有效的指导现场开挖施工,保障工程施工安全。

Safety monitoring plays an important role in the construction of underground water diversion tunnels.Monitoring data can faithfully reflect the deformation process and stress changes of surrounding rocks during excavation and construction.The underground tunnel at KSVII bid section of Dongjiang Water Diversion Project is buried too deep.During the excavation,the construction branch tunnel intersects with the upstream main tunnel and the downstream main tunnel.The span of the intersection is large,the geological conditions are poor,and the surrounding rock stress is complex.In order to analyze the deformation,stress distribution and development characteristics of the surrounding rock of the deep-buried water diversion tunnel,safety monitoring data can be obtained in a timely manner by installing buried monitoring instruments.Based on the analysis of monitoring data,the deformation and stress changes of the surrounding rock are analyzed.The results show that the displacement and deformation of the surrounding rock is basically consistent with the change trend of the internal stress of the surrounding rock.The monitoring instrument value is affected by the excavation,the stress of the surrounding rock is released,and the creep of the surrounding rock structure affects the change rate of the instrument measurement value.The change rate continues to increase;with the completion of tunnel excavation,the stress of the surrounding rock is readjusted and gradually released to the free surface,resulting in varying degrees of increase or fluctuation in the monitoring value during the subsequent monitoring process.After the stress adjustment of the surrounding rock is completed,the monitoring value gradually becomes stable;during the excavation,the disturbance to the surrounding rock should be alleviated and timely support should be provided to ensure the safety of the project construction.The study results can effectively guide on-site excavation construction and ensure project construction safety.