Study On Construction Technique Of Cut-And-Cover And Mining In Ruyifang Station Of Guangzhou Metro

In large cities, it is difficult to organize traffic in station construction because of the interference from existing ground traffic and buildings if we adopt opencut method. Although we can avoid these problems with the method of undercut, the technical complications and economy cost will be enlarged. If we can make use of the combination of both ways, we can reasonably adopt opencut or undercut along the conditions of the station location for the convenience of site organization thus the construction difficulties and works cost may decrease.This paper demonstrates the application of the combinated technique of cut-and-cover and mining method in subway station construction based on the construction of Ruyifang Station in Guangzhou Subway Line VI.Firstly,Based on the actual conditions of the location of Ruyifang Station and comparison to ordinary ways, this paper raises a method of opencut in combination with undercut and makes a series of corresponding structural calculations, that gives the construction support plan a foundation in theory. Secondly,the paper details the methods and techniques about construction of support structure for underground continous walls in opencut foundation pits. Also it demonstrates the construction methods and techniques in excavation of opencut foundation pits and support systems.Moreover,this paper introduces how to organize construction and techniques in building of tunnels for station platform and transversal passways. The introduction of techniques and methods used in pre-support, initial support, and second lining in undercut construction provides reference for contractors.Finally,it also provides a necessary introduction to construction of structural water-proof and observation to ground buildings, the result can give a reference to contractors who implements similar project in cites.