Excavation Technology of Shallowburied Portal Section of
Largespanned Smallspaced Twintube Tunnel in Soft Ground
HUANG Xin-She, CAO Zheng-Chi
1. Hangzhou Company of China Railway Tunnel Group Co., Ltd., Hangzhou 310030, China;
2. Scientific Research Institute of China Railway Tunnel Group Co., Ltd., Luoyang 471009, Henan, China