Study On The Excavation And Cave Mud Of Railway Tunnel For The Influence Of Almost Meeting Engineering

In recent years, as China’s highway and railway construction to continue topromote the southwestern mountains, the growing tunnels built in karst areas. In karsttunnel construction process prone to sudden mud, water inrush and other geologicaldisasters, the safety of the tunnel construction has a great impact. Due to the specialgeological conditions limit karst areas, which will result in a new tunnel near theexisting tunnel construction, thus creating a large number of proximity works. How toevaluate the impact of karst disaster tunnel itself and the proximity of engineering,designing and construction of the tunnel became a key technical issues. Therefore, thestudy of karst tunnels adjacent construction becomes particularly important.This paper to create a new local Xuyong-Dacun railway line and Naqianhighway that has been built as typical example, the summary of the law of the karstarea, a large number of investigations on the basis of on-site build construction ofkarst tunnels Proximity three-dimensional model, Analysis in progress under theinfluence of various karst conditions existing project. The main results obtained are asfollows:(1) Through the karst environment of the study area in-depth research, analysisshows that more performance for the dissolution of surface karst depressions andcorrosion fracture zone, and a few sinkholes. More performance for the dissolution ofunderground karst sewing, melting tank filled with mostly vertical development andmud, mud cave is similar to filling the cave.(2) Karst tunnel site was found by studying the laws summarize the following: theimpact of carbonate rocks①By karst study area, which contains coarse limestone,karst development provides a good material foundation.②The study area and itsvertical structure of surface karst development are closely related.③The study areafrom the valley to the watershed area, the extent of karst waning.(3) Types of karst collapse mud process and a detailed description of the reason,sudden partial collapse of mud process performance, deformation accumulation, traction collapsed mud sudden stroke four processes; Features include partial collapseis threatened, highlighting the soft plastic material states plus clay stone, highlightinglasted more than20hours. As well as the law of karst tunnels sudden mud produced adetailed study, while the sudden mud tunnels treatment studied and proposed thecorresponding mud irruption emergency, preventive measures and treatment for.(4) Using numerical analysis methods, the construction process for theconstruction of the upper and lower cross the tunnel under the karst environmentproximity, which establish the appropriate three-dimensional finite element modelunder different conditions on the construction characteristics of the mechanicalbehavior of tunnel lining structure of the two existing tunnels depth research hasdetermined whether tunneling construction structural mechanics and safety lawsaffecting existing tunnels.