CHENG Lin1,2,YANG Chengyong1,LU Qingquan3?覮,MA Wenhui1,CHE Jingke4
(1. School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;2. China Construction 2nd Engineering Bureau Ltd,Beijing 100160,China;3. Beijing Metro Construction Administration Co Ltd,Beijing 100068,China;4. Beijing General Municipal Engineering Design & Research Institute Co Ltd,Beijing 100082,China)