摘要
中洞法施工时,由于中洞的二衬浇筑与中洞开挖和初期支护之间的时间间隔较短,中洞二衬结构在初期支护变形尚未完成时已经参与共同工作,同时在侧洞开挖时,围岩体已经形成的力学平衡再次被改变,需要与衬砌结构共同变形重新达到新的平衡,已形成的中洞二衬结构的受力状态将又一次发生变化,这些问题在实际工程中并未得到深入考虑和研究,造成一系列工程问题。本文作者以北京地铁五号线典型的中洞法车站为例,对中洞法地铁车站的衬砌结构进行施工阶段的全程力学分析研究,阐述其在各个施工阶段的力学行为,确定了最不利荷载工况,并对中洞法地铁车站结构的断面形式进行了一定的优化。
In practice it is found that the construction time slot between initial lining and secondary lining for center drift excavation method is less than that for traditional shallow tunnel construction method,so the secondary lining will take on the weight of surrounding rock before the distortion of initial lining have been finished.At the same time when the side drift is excavated,the load on the secondary lining will change again and accordingly the internal force and the distortion of secondary lining will also adjust itself.Based on the typical station constructed by center drift excavation method on Beijing metro line 5,the mechanical characteristics of the secondary lining of the station under construction were studied to determine the unfavorable loading state.The optimum transect shape of subway station by center drift method is found.
出处
《地下空间与工程学报》
CSCD
北大核心
2010年第4期828-832,共5页
Chinese Journal of Underground Space and Engineering
关键词
中洞法
二衬结构
围岩
FLAC3D
数值分析
center drift excavation method
secondary lining
surrounding rock
FLAC3D
numerical analysis
