Monitoring Measurement And Safety Evaluation Of Inside And Outside The Tunnel In The Construction Process Of The NanHu Subway Station

Chongqing rail transit link South Lake Station is located in the southeast quadrant of the road and the big stone road interchange,along the east-west road Strait arrangement in which the road across the Strait of stone road.Two roads are both the main roads of the city with heavy traffic.The main station for the bi-directional is the single hole bored tunnel,located just below the Rock Road Interchange,underground two layer Island,the largest section excavation width 25.09 m,excavation height of 21.01 m,dome casing 12.79 ~ 23.75 m,the thinnest cover rock about 6.7m.The main station is the super Shallow or the Shallow tunnel.The main station uses drilling and blasting method of construction.Since the station belongs to the Super large section tunnel(clearance section area>100m2).Itself when the excavation is more unfavorable,the stability of the tunnel itself has a big risk,and may lead to ground subsidence,or even collapse,thereby causing the neighboring construction(structure)building theincluding roads,bridges,houses cracking,tilt,even collapse and other damage or destruction.In this paper,the influence of the stability of surrounding rock and Zhou Bianjian(structure)on the stability of the surrounding rock during the excavation of the two phase of the railway link in Chongqing city is studied,on the basis of theoretical analysis,Using the finite element software MIDAS / GTS of tunnel surrounding rock and support structure stress,strain,displacement,around built(structure)to build the settlement,inclination of simulation calculation and analysis,and on the station and the surrounding building(structure)to build the security risk assessment and risk control measures are discussed.The main contents are as follows:(1)The basis and significance of the selected topic;(2)Influence of tunnel construction on surrounding rock stability and surrounding ground building(structure);(3)Contents and methods of monitoring and controlling measurement of station tunnel and ground construction(structure);(4)Using MIDAS/GTS to simulate the construction of the South Lake Station Tunnel(including the risk of construction(construction)in the area;(5)Theoretical calculations and monitoring data were analyzed,determining the correctness of the theoretical value;(6)To the South Lake station itself and the existing building(structure)building materials for safety assessment,and put forward the safety assessment standards.