Research and Practice of Monitoring Measurement Security Technology of Portal Excavation for Mountain Tunnel

摘要

In the construction process of portal excavation for mountain tunnels, the improper risk management and control result in the instability of the front slope, deformation of the tunnel portal and subsidence of the roof. In order to carry out the purport of dynamic design and informationalized construction, ensuring the quality and security of portal construction, a three-dimensional and multi-level monitoring measurement system is indispensable. Combining with the practical monitoring measurement of the portal excavation of the tunnel exit in a mountain tunnel in Chongqing, the monitoring measurement system construction process of portal excavation for mountain tunnels is expounded. Besides, the portal stability analysis method and the monitoring information feedback procedure based on multi-source data for the three-dimensional and multi-level monitoring measurement system are analyzed.