Study On Safety Monitoring Construction Roads Through Large Section Clayey Loess High-Speed Rail Tunnel

With the deepening of the western development and "the Belt and Road" to promote the construction of railway construction in western China with each passing day. The pace of the western high-speed railway construction is also accelerating, due to the western topography and other reasons, the tunnel road network construction in the West is almost essential, and clayey loess the special geological conditions of the construction of the tunnel safety is very negative, combined modern high-speed railway tunnel cross-sectional area requirements expand, so the study of the structures through construction safety monitoring large section loess tunnel is necessary.This paper segment wear Avenue Fuxi TianShui City, and the day the North section of high-speed passenger dedicated engineering at Borland Weihe River tunnel, under a large clayey loess section Tunnel high-speed rail construction of urban roads were monitored security research. Mainly through the field wearing the day the North section of high-speed construction monitoring measurement wear Xi Huang Weihe River Avenue and under the next tunnel, drawn from the analysis of the formation of its tunnel construction crown settlement, convergence of surrounding rock and ground subsidence during construction value displacement of the law. ANSYS finite element analysis software for the construction segment tunnel simulation, test data analysis resulting in the conclusion at the same time can be further analyzed Ground Movement Laws Caused by Tunnel Construction. The conclusions not only as a theoretical basis for the safety of the tunnel construction, but also provide a reference for similar project design, construction and monitoring.Through the special guest at Borland Xi Huang Weihe River Tunnel Boulevard and at high speed through the day the North resulting test data and numerical simulation of monitoring the construction site analysis of the results obtained:(1) During the construction, excavation step has a huge impact on the vault settlement and surrounding rock convergence; convergence impact on surrounding rock tunnel construction on vault settlement of more than;(2) substantially in the vault final settlement between 30 mm ~ 50 mm, the need to stabilize for about 30 days;(3) Tunneling on the road surface impact of a range of about 20 m inside the tunnel center line;(4) double side drift method in clayey large section loess tunnel construction in the absence of exceptional circumstances affecting construction safety can be guaranteed. Construction of surface urban roads less affected, does not affect normal use.