Study On The Mechanical Characteristics And Construction Technology Of Shallow Embedded Bias Neighborhood Tunnels

Neighborhood tunnel is a tunnel structure interposes between separated tunnel and multiple-arch tunnel, on one hand it can overcome some outstanding problems such as inflexible expanding line,large land area and high slope in separated tunnel,on the other hand it is easier to control the construction quality and has a shorter duration and a lower cost than multi-arch tunnel.Neighborhood tunnel has been widely used in the construction of highway tunnel in mountain area currently.This paper is based on the Tian-LuoWo tunnel of Yan-Ru expressway in HuNan Province. With the method of numerical simulation and field measurement, I carried on my study on the construction technology and mechanical characteristics of shallow embedded bias neighborhood tunnels.The main research are as follows:1.This paper summerized some commonly used calculation methods of tunnel surrounding rock pressure,on this basis,did some theoretical calculations about the surrounding rock pressure of shallow embedded bias neighborhood tunnels and obtained distribution and the change law of surrounding rock pressure in case of overburden thickness and land slope changes.2.Considering the properties of Tian-LuoWo tunnel,the construction sequence,tunnel construction method,the distance between the two working faces and the bench length of shallow embedded bias neighborhood tunnel are analyzed and compared,by adopting numerical means.The optimal construction schemes are proposed,meanwhile,the mechanical properties and laws of shallow embedded bias neighborhood tunnels are analyzed.3.With the method of numerical simulation,this paper analyzes the influence law of shallow embedded bias neighborhood tunnels and proposes the minimum reasonable clear distance under the V rock.The deformation of surrounding rock and the stress characteristics of supporting structure of shallow embedded bias neighborhood tunnels in different shared rock reinforcement schemes are analyzed.The most reasonable shared rock reinforcement scheme about Tian-LuoWo tunnel was achieved.4.Based on the results of numerical simulation and field measurement,the mechanical characteristics of surrounding rock stress and supporting structure of shallow embedded bias neighborhood tunnels are analyzed.