The Shallow Depth Excavation Subway Tunnel Construction Control Technology And Surface Subsidence In Complex Geological Conditions

With the development of our cities, the traffic problem has become a problem restricting the development of the city. The city subway to become an effective means to slow urban traffic pressure. Mining method subway construction using a construction. City metro tunnel excavation will cause surface subsidence, causing serious losses will be the quality of urban residents’personal safety of life and property as well as subway project. Therefore, during the urban subway tunnel construction process, paying particular attention to surface subsidence caused by the construction.In this paper, we analyze the influencing factors and regulations of rock pressure and rock transformation of shallow-buried excavation, and introduces the current commonly used shallow depth excavation of surrounding rock control technology. Excavated Metro Tunnel Engineering Dalian Metro Line202tenders to promote the spring range by calculating the step method, to retain the core of indigenous, full-face method of three construction methods the deformation of the concrete layer by the effected control Excavation Construction of a tunnel around the jet, the construction phase of tunnel surrounding rock around the stress distribution of the vertical displacement of the distribution of plastic zone, soil excavation section upper support structure anchor in force, We got that:1Ground settlement:the value reached-7.68mm by the step method;the value reached-7.18mm by retain the core method, the value reached-7.68mm by the full-face method.2The displacement of concrete layer:the value reached-20.12mm by the step method; the value reached-17.20mm by the retain the core method; the value reached-33.22mm by the full-face method.Calculated as follows:full-face method caused surface subsidence, and the step method and retain the core of indigenous cause surface subsidence is quite. Combining with the characteristics of locale, the most suitable method of construction of the project is the step method.Found by actual measurement:step construction method the longitudinal extent of the surface settlement of1.3D (D is hole diameter) tunnel excavation vault settlement and hole weeks convergence measuring points of the longitudinal distance of about1D. Crown settlement value of approximately two times the hole weeks convergence value. The development trend of the three are basically the same.