软岩偏压隧道地表沉降规律研究

Study on Surface Settlement Law of Soft Rock Bias Tunnel

对云南省某软岩隧道监控实测数据进行了分析研究。根据研究结果,隧道进洞以后随着掌子面的推进,将地表沉降分为开始沉降阶段、加速沉降阶段、缓慢沉降阶段、稳定阶段。当隧道施工至监测断面前±10 m范围时,此时地表沉降速率最大,且该阶段的沉降变化量可达到最终沉降值的75%;随着掌子面继续掘进,地表进入缓慢沉降阶段,该阶段一般持续至掌子面穿过监测断面30 m处;之后地表稳定,沉降速率≤0.1 mm/d。该分析方法及结论可为类似工程提供借鉴和参考。

This paper analyzes and studies the monitoring data of a soft rock tunnel in Yunnan province.According to the research results,the surface settlement of the tunnel is divided into initial settlement stage,accelerated settlement stage,slow settlement stage and stable stage with the advance of the palm face after the tunnel enters the tunnel.When the tunnel construction reaches the range of±10m in front of the monitoring fault,the land surface settlement rate is the largest,and the settlement change amount in this stage can reach 75%of the final settlement value.With the continued excavation of the palm,the ground surface enters a slow settlement stage,which generally lasts until the palm passes through the monitoring section 30m.After that,the surface is stable,and the settlement rate is less than 0.1mm/d.The analysis method and conclusion can provide reference for similar projects.