Study On The Impact Zoning And Countermeasures Of Nearing Construction Between Tunnel And Building

This paper relies on the national key research and development plan "Structural risk monitoring,key technology of safety control and demonstration of typical construction projects adjacent to existing urban roads/bridges/tunnels".Studying the impact zoning and countermeasures of the nearing construction between tunnel and building.Mainly completed the following work.(1)Through relevant paper and literature,researching the current research status of the mechanics principle,influence zoning and countermeasures of the tunnel construction is obtained,to facilitate our future research.(2)Using strength reduction method,we calculate the safety factor for the construction of the tunnel and the building in close proximity.Through comparison,we select the combination of ultimate shear strain and plastic zone penetration as the criterion of surrounding rock instability.Choosing the safety coefficient contour of the upper limit mechanical index of the surrounding rock of this level is taken as the range of the strong influence zone,the safety coefficient contour of the lower limit mechanical index of the surrounding rock of this level is taken as the range of the weak influence zone,and the outside is the range of no influence zone.Using the least squares method,we get the general fitting curve and formula.(3)Through calculation,we get the safety factor under 8 different working conditions of single enlarged foundation and 160 different working conditions of single tunnel construction,get the general law of the construction safety factor under this condition.(4)Choosing two-lane and three-lane road tunnels,foundation width of 16 m and 32 m,four directions of 0°,30°,60°,and 90° and eight close distances,we obtain the safety factor and contour of the new tunnel close to the existing building under 160 different working conditions,the change law of the safety factor and related parameters.On this basis,we get the general influence partition and fitting formula.(5)Choosing two-lane and three-lane road tunnels,foundation width of 16 m and 32 m,four buried depths of 6m,13 m,30m,and 50 m,horizontal distance between the center line of 11 tunnels and the center of the foundation,we obtain the safety factors and contours of buildings built on existing tunnels under 256 different working conditions,the change law of the safety factor and related parameters.On this basis,we get the general influence partition and fitting formula.(6)Combined with the actual project,the Liujiang section of Chongqing Rail Transit Line9 crosses the abutment foundation of Huanghuayuan Bridge to verify the scientific and effectiveness of the influence zoning and the fitting formula,and put forward relevant countermeasures.Through monitoring,we verify the effectiveness of countermeasures.