The Influence And Control Measures Of Tunnel Construction On The Upper Part Of The Existing Building Structure

The new era has witnessed the development of transportation.Many medium and large sized cities in China are now building metro system,which needs to dig tunnels,thus forming another transportation system such as metro tunnel,railway tunnel and highway tunnel. During the construction of city tunnels, it is inevitable to pass some places on top of which stand buildings, causing decline and deformation of the earth's surface as well as bad influence towards the upper layer and its surrounding buildings. This dissertation is aimed at the research of the influence that tunnel digging may have towards its upper existing buildings with such research methods as theoretical analysis, numerical simulation and field monitoring, under the real case studying what influences Hualinping tunnel construction in Lanzhou has had towards Ee'an residential building, prioritizing the tunnel excavation, The internal force and deformation of buildings, deformation of raft foundation and decline of surface around the tunnel and buildings,and putting forward the preventive and treatment measures for the influence that tunnel digging may have towards buildings. The major research methods and conclusions are as follows:1. With the software of MIDAS/GTS to set up a model database of the mutual effect between tunnel digging and surrounding buildings. To figure out the influential relationship between tunnel digging and the upper or its surrounding buildings under CRD method with different thickness of raft foundation by comparing internal force and deformation of buildings, deformation of raft foundation and decline of surface around the tunnel and buildings. Acquired the four stages in which the upper building deformation is in accordance with the surface decline caused by digging tunnels, that is, the left side of the raft foundation declines more than the right side, the vertical displacement of the left beam is larger than the right one, the horizontal displacement of the beam increases gradually from the bottom to the top, and the surface decline is in accordance with the Peck Settlement Curve.2. To analyze the real time database(deformation, crack), to seek out the change rules of the deformation and decline of upper building and the development of cracks and to compare it with numerical simulation rules so as to assure the correctness of numerical simulation. The on-the-spot decline trend basically conforms to the numerical simulation result. Given the on-the-spot data is a little larger, the real situation of the field should be taken into consideration. The development of cracks in the building is a little lagged compared with the decline of buildings.3. To find out solutions on dealing with the influence that tunnel digging has towards its upper building structure, combining with background engineering and applying these solutions to background engineering. Acquired desirable result after reinforcement to rectify deviation on background engineering through observation.