Study On New Construction Surrounding Rock Stability Of Large Section Tunnel And Its Impact On The Existing Tunnel Safety

Nowadays, with domestic traffic planning continuous improvement, China has entered a highway transportation construction climax of rapid development. Taking into account China’s urban road congestion, both have occurred near the new highway tunnel Case highway tunnel construction. How to ensure the normal operation of the existing highway tunnel?New construction safety? Engineering has been an unavoidable problem.1. Combined with the project before the study area, the construction division of factors af fect the stability of surrounding rock of large cross section tunnel, and as a basis for building a hierarchical model, the establishment of index membership function and sensitivity of each fa ctor fuzzy Overview. The results showed that: factors affecting the stability of surrounding roc k Large Section Tunnel Construction heavier to light as follows: drilling blasting, tunnel secti ons, lithology, topography and surrounding environment.2.Based on ABAQUS finite element software to establish numerical model considers the change "depth, spacing and cross section form" and a total of 12 kinds of programs, and select a typical cross-section of the overall stability of the surrounding rock of large cross section tu nnel construction were evaluated. The results showed that: depth, pitch and cross-section in th e form of both on the stability of surrounding rock, just in terms of working conditions in the study area, when the tunnel when the line spacing in 1.5D ~ 2.5D, through-wall rock deformat ion trend, surrounding rock stability less; when the pitch 2.5D ~ 3.0D, basic construction safet y controllable; when the spacing is greater than 3.5D, higher construction safety tunnel stabilit y(D is the diameter of the excavation hole).3.To carry out the surface subsidence in tunnel construction process, the convergence of surrounding rock and vault displacement monitoring work on the construction of new large cr oss section tunnel surrounding rock stability analysis is used to guide the construction site.4.In order to study the new tunnel blasting excavation on the existing tunnel safety, the p aper carried out under different amounts of explosives and blasting distance conditions of vibr ation velocity, frequency and duration time monitoring to optimize the amount of blasting exp losives.