Abstract Taking the east extension project of Beijing Metro Line 7 as a project case, in order to ensure the sched? ule of the opening and operation of the line, the mechanical and electrical installation and decoration of stations,construction of shield tunnels and freezing for cross passages had to be carried out simultaneously. Based on this,during construction, the construction schedule, site conditions (ground surface and interior of stations and tunnels),freezing effect and cost were comprehensively considered, the construction technical scheme that two cross passages share one freezing station was proposed, that is, the freezing station was located in the middle of two cross passages of the tunnel that has achieved breakthrough. By means of optimizing the selection of freezing station units, layout of freezing pipeline, tunnel segment pre-reinforcement support system and other technical measures, synchronous construction of shield tunnels and freezing reinforcement was achieved. According to monitoring and data analysis of the construction process, the development law of the freezing wall and the conditions for the safe excavation of the passages were summarized, and countermeasures for the problems were proposed, such as rise of the cooling water temperature on the site and the ambient temperature. The results show that the construction scheme and relevant technical measures are safe, effective and feasible.
Abstract：
Taking the east extension project of Beijing Metro Line 7 as a project case, in order to ensure the sched? ule of the opening and operation of the line, the mechanical and electrical installation and decoration of stations,construction of shield tunnels and freezing for cross passages had to be carried out simultaneously. Based on this,during construction, the construction schedule, site conditions (ground surface and interior of stations and tunnels),freezing effect and cost were comprehensively considered, the construction technical scheme that two cross passages share one freezing station was proposed, that is, the freezing station was located in the middle of two cross passages of the tunnel that has achieved breakthrough. By means of optimizing the selection of freezing station units, layout of freezing pipeline, tunnel segment pre-reinforcement support system and other technical measures, synchronous construction of shield tunnels and freezing reinforcement was achieved. According to monitoring and data analysis of the construction process, the development law of the freezing wall and the conditions for the safe excavation of the passages were summarized, and countermeasures for the problems were proposed, such as rise of the cooling water temperature on the site and the ambient temperature. The results show that the construction scheme and relevant technical measures are safe, effective and feasible.
CHEN Jingang GUO Qiang ZHOU Hailong HUAI Wenbao DONG Xiaoqi
.Construction Scheme and Application Analysis of Synchronous Construction of Subway Shield Tunnels and Freezing Reinforcement for Cross Passages[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(1): 233-240
2023, Vol. 60 