Anaysis of Construction Techniques for a Metro Tunnel Approaching an Existing Station
(1 Beijing Jiaotong University, Beijing 100044; 2 Xi'an University of Architecture and Technology, Xi'an 710055; 3 China Railway Construction Bridge Engineering Bureau Group Co. Ltd., TianJing 300300)
Abstract：
Construction of a new metro tunnel approaching an existing metro station may cause deformation of the station structure, affecting normal operation of the metro. Based on Beijing Metro Line 7 passing under the Shuangjing Station of the existing Beijing Metro Line 10, a numerical simulation was carried out regarding the deformation and force applied to the station's main structure, the metro track support of the running tunnel due to full-face tunnel excavation, and the bench method excavation and CRD excavation of the metro running tunnel approaching the existing station. A contrastive analysis was undertaken regarding the deformation characteristics of the existing station and track under different excavation schemes, and an excavation scheme was determined for the running tunnel approaching the existing station considering deformation control and force variation factors. A numerical simulation was performed aimed at the reinforcement effect for deformation control of the existing station and track under different reinforcement measures when the CRD method was used, and parameters of grouting reinforcement were determined, such as reinforcement scope and length. Analysis of site monitoring results shows that the optimized CRD construction method and reinforcement measures, such as reinforcing the interbed between the left line and right line, the stratum at the working face, and the area within 3m outside the left and right external contour, can guarantee the safety of the existing station. The deformation rate of the existing track is no more than 0.04 mm/d and the accumulated deformation of the main structure of the existing station is less than 10mm.
WAN Liang-Yong-1,
SONG Zhan-Ping-2,
3 etc
.Anaysis of Construction Techniques for a Metro Tunnel Approaching an Existing Station[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(1): 168-176
2015, Vol. 52 