CONSTRUCTION SCHEME OPTIMIZATION OF SMALL ANGLE ON THE ACROSS THE EXISTING SUBWAY TUNNEL OF QINGDAO METRO

With the increasing of domestic demand for subway construction, the subway construction technical requirements are more stringent. This paper aims to solve the technical problem in the upper cross-segment with small angle and clear distance in the subway tunnel. Based on the existing engineering practices of the section of the Qingdao metro, the engineering geologic condition, regional architectural environment and mechanical properties of rock and soil mass are analyzed combining with the related engineering examples. Comprehensive application of the curtain method, advanced small duct, self-advance pipe shed and anchor, grid and other technical means are optimized for the construction scheme. The improved construction scheme utilizes some supporting technology to play an important role in reducing the construction cost and speeding up the construction progress. The research results can provide reference for this kind of projects under similar conditions.