Application of Double Side Drift Method in Construction of Extra-large Cross-section Hard Rock Station Tunnel Located in Busy Urban Area

Linjiangmen station tunnel,which is located in busy urban areas,has complex surrounding environment.The area of the excavation cross-section of the tunnel reaches 420.96m2 and the dimensions of the tunnel cross-sections change frequently.The tunnel runs through hard sandstone.There is no experience available in China that can be used as reference for the construction of the tunnel.Therefore,there exist great difficulties in the construction of the tunnel.The tunnel is constructed by means of double-side-drift blasting method.Due to the adoption of appropriate controlled blasting technologies,integral lining technologies(with the core rock benches being kept),monitoring and measurement technologies and other matching technologies,the tunnel is completed with safety,high quality and high speed and good economic efficiency is achieved.The construction technologies for the tunnel are presented in the paper.