Research On Metro Station Construction With The Method Of Cover-Excavation Consequent Operation

Most of the subway stations in China are constructed by open-cut method (only a few by shallow cover subsurface excavation method where geological conditions allow). There are some instances of partial cover-excavation when going through arterial roads in cities. However, the construction of this station by cover-excavation method is the first of its kind in a busy city arterial road.This paper first makes a careful study of the engineering environment, engineering hydrogeology of the Kexueguan Station of Shenzhen Metro, expatiates on and compares the technical features of cover-excavation method, reversed cover-excavation method and subsurface excavation, illustrates the key technology of cover-excavation method proposed for the Station. Secondly, the paper discusses the main functions of the temporary road system, advances the feasibility and necessity of optimum design. Further on, the paper makes a mechanical analysis of the optimum design with emphasis laid on longitudinal partition coefficient, re-examination of structure' s strength, rigidity and stability. Thirdly, with regard to stability of foundation pit excavation and support, the paper goes on to make analysis of limited plastic deformation and finite element simulation. Proper construction procedures and technical measures are decided by computing the two excavation methods, thus provide theoretical guarantee for safe construction.Cover-excavation method is a new kind of construction method, in addition, the paper illustrate the main features of proper construction procedures, equipment scheme, material supply, construct ton management and counter measures.Overall process measurement are conducted on mechanics parameter changes of foundation pi t, stress and strain of' support structures, and the results are analyzed to guide the adjustment and consummation of various technical measures, thus cover-excavation method can be smoothly implemented.