摘要
随着高铁列车运行速度的提高,气动荷载成为隧道结构重要的附加荷载,尤其是素混凝土二次衬砌存在初始缺陷时,气动荷载将对衬砌安全有较大影响。针对素混凝土二次衬砌存在初始裂纹和厚度不足缺陷的情况,分别采用基于断裂力学的数值流形方法和基于荷载-结构模型有限元法,对2种衬砌缺陷在气动荷载作用下的影响开展研究。研究结果表明:隧道素混凝土二次衬砌存在初始缺陷时,气动荷载对缺陷部位的耐久性和长期稳定性有很大影响;隧道衬砌存在裂纹时,在气动荷载作用下,裂纹尖端应力强度因子增大150%以上;衬砌厚度不足时,在气动荷载作用下,缺陷部位拉应力增大54%,衬砌处于“拉-压”循环受力状态。研究结果可为高铁隧道素混凝土结构的长期稳定性及耐久性设计提供参考。
With the increase in operation speed of high speed railway trains,the aerodynamic load has become an important additional load for tunnel structures.Especially when there are initial defects in the plain concrete secondary lining,the aerodynamic load will have a great impact on lining safety.The numerical manifold method based on fracture mechanics and the finite element method based on the load-structure model were used to study the impact of aerodynamic load in two defect cases,i.e.initial cracks and insufficient thickness of plain concrete secondary lining.The results indicate that when there are initial defects in the plain concrete secondary lining,the aerodynamic load has a great impact on the durability and long-term stability of the defective parts;when there are cracks in the tunnel lining,the stress intensity factor at the crack tip increases by more than 150%under the aerodynamic load;when the lining thickness is insufficient,the tensile stress at the defective part increases by 54%under the aerodynamic load,and the lining is in a“tension-compression”cyclic state.The results of this study provide a reference for the long-term stability and durability design of plain concrete structures of high speed railway tunnels.
作者
唐文国
任玉鹏
丁祥
TANG Wenguo;REN Yupeng;DING Xiang(China Railway Lanzhou Group Co.,Ltd.,Lanzhou Gansu 730030,China;Yinchuan Construction Directorate,China Railway Lanzhou Group Co.,Ltd.,Yinchuan Ningxia 750000,China;China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 102600,China)
出处
《中国铁路》
北大核心
2024年第2期69-74,86,共7页
China Railway
基金
中国铁路兰州局集团有限公司科研计划项目(ZTTL2018-76)。
关键词
高铁隧道
气动荷载
素混凝土
二次衬砌
初始缺陷
high speed railway tunnel
aerodynamic load
plain concrete
secondary lining
initial defects
