公路隧道拱顶下沉监测点埋设深度研究

Study on Buried Depth of Monitoring Points of Vault Crown Settlement in Highway Tunnel

针对隧道监控量测洞内测点埋置深度取值模糊,无法较为全面真实的反映围岩位移变化情况的问题。首先采用数值模拟的方法研究不同深度围岩位移变化情况。然后依托实际工程采用现场监测的方法,采集Ⅲ、Ⅳ、Ⅴ级围岩隧道不同埋深处拱顶下沉监测数据。通过对监测数据的拟合分析,得出山区公路隧道拱顶下沉监测点埋设深度建议值,分别为Ⅲ级围岩30cm、Ⅳ级围岩40cm、Ⅴ级围岩50cm。

Aiming at the problem that the buried depth of monitoring points in tunnel monitoring measurement is ambiguous,which is impossible to reflect the displacement change of surrounding rock,in this paper,firstly,the numerical simulation method was used to study the variation of surrounding rock displacement at different depths;Then,the field monitoring method was used to collect the data of the vault crown settlement at different depths of the III,IV and V surrounding rock tunnels by relying on the actual project.The recommended values of the buried depth of the vault crown settlement points were obtained by fitting analysis of the monitoring data,which are 30cm of gradeⅢsurrounding rock,40cm of IV gradeⅢsurrounding rock and 50cm of gradeⅤsurrounding rock respectively.