Proximity Subway Tunnel Construction Impact On The Existing Pit

China’s subway construction has made great progress in the recent years. Since thedifference between running tunnel and station foundation pit project construction ontime effect, subway tunnel excavation retaining wall or rock may easy to form thephenomenon of rock instability and jeopardize the safety of construction when it formedon the90°pit wall or the hole hard. So the important signification is that it can seek themethods to improve the rock stability when knowing the mechanical characteristics ofconstruction and settling features with this special constrution background.This paper is based on the construction project of Eling to Lianglukou runningtunnel and Lianglukou Pit of Chongqing Metro Line1. Owing to involving the questionof construction efficiency, After tunneling in vertical excavation formed on the highslope. To find out more reasonable tunnel excavation method and support programs(Including the formation of tunnel support programs and support programs), Proximityto protect both the construction pit area entrance with security, Application of finiteelement software MIDAS/GTS, Construction of three-dimensional numericalsimulation of different working methods to analyze hole excavation of the wholeprocess, Analysis of the force deformation characteristics under various conditionssurrounding rock and support system, Combined with the actual scene of thecomparative analysis of monitoring data, The details are as follows:①Subway Tunnel; Pit Proximity; Numerical Simulation; Rock stability Review ofthe status of surrounding rock stability through reading relevant literature and out of thehole excavation methods, tunnel and cave-side support, Before human factors on thestability of theoretical guidance portal section, Mechanical behavior of tunnel entranceon the actual engineering geological conditions provide the basis for analysis.②Research out of the hole excavation and construction of the basic laws ofmechanics, Dynamic three-dimensional elastic-plastic model of the whole process of theconstruction of dynamic of Step method were established, the whole paragraph surfacemethod, side drift method+support excavation methods, Analysis the forcecharacteristics of vault, arch back and arch rock under different working methods,Mechanical properties of bolting or the basic law of surface subsidence and Vault.③Relying Eling tunnel junctions to two existing excavation instance Proximity,Under which specific projects to build three-dimensional model to analyze the geological environment, The whole process of the construction of imports Proximityparagraph vault pit and surface rock subsidence analysis, Settlement analysis and modelresults with the actual monitoring data were analyzed, Draw relevant conclusions.④Seek a reasonable construction scheme, Based on the analysis and comparativeanalysis of the mechanical properties and surface subsidence features vaultedconstruction process of surrounding rock and support structures on, Puts forward somemeasures to improve the pit Proximity stable construction segment.