Analysis Of Construction Influence Of Double Line Shield Tunnels Passing Through Existing Building In Soft Soil

Recent years in the construction of urban subway, the Double Line Shield Tunnels would have been adopted in most cases. This formation is more complicated than a Single Shield Tunnel in influence on stratum and leads to severer ground surface settlement. At the same time the disturbance of soft soil increases the difficulty in controlling the ground surface settlement. When the tunnels go through buildings, negative effects would be brought by imperfect control in ground surface settlement.Based on the characteristics of soft soil in Suzhou, the research background of Suzhou shield tunnel engineering, the monitoring data at the scene, the construction parameters of Shield Tunnel and the numerical simulation, the regularity and controlling factors of building settlement led by the construction of parallel shield tunnels would be analyzed in this thesis.The main research contents are following:1.Referring to Double Line Shield Tunnels in soft soil in Suzhou, the Shield tunneling parameters are analyzed. The setting of soil pressure, the setting of grouting parameters and the controlling of shield posture, points of EPB shield construction are analyzed and summarized.2. Through the numerical simulation of FLAC3D program of Shield Tunnels passing through existing building, the influence of different factors on ground surface settlement and building settlement are researched, such as the size of buildings, the position of buildings, the distance between tunnels, tunneling direction and so on.3. The monitoring data of building settlement led by parallel shiled tunnels in a number of regions in Suzhou are analyzed. In combination with the related factors, such as the geographical positions of tunnels and buildings, the conditions of stratum, tunneling parameters and so on, the process and regularity of ground surface settlement and building settlement are researched. The divergences of the contruction parameter in tunnelling lines and the controlling measures of building settlement are analyzed. The relation between shield posture and synchronous grouting and single-day settlement, the influence of the halting of shield on settlement are researched.