摘要
通过现场监测和数值模拟,研究了中兰客运专线盘岘山大断面黄土隧道二次衬砌的受力特征。结果表明:接触压力、钢筋轴力、混凝土应力随时间变化大致可分为施工扰动阶段、变化阶段和稳定阶段,仰拱受力波动幅度较拱墙大,达到稳定的时间更长;接触压力沿洞周不均匀分布,边墙以上呈双耳状分布,仰拱处呈哑铃形分布,且仰拱整体接触压力大于边墙以上部分;理论与实测荷载作用下二次衬砌内力与分布规律差异显著。安全系数最小值在理论荷载作用下位于拱顶和左右拱肩,在实测荷载作用下位于仰拱与边墙交界处。实测结果表明基于松动压力的理论荷载不能表征砂质黄土地层二次衬砌结构的实际受力特征。
The mechanical characteristics of secondary lining of sandy loess tunnel with large cross-section in Panxian Mountain on Zhongwei-Lanzhou Passenger Dedicated Line were studied through field monitoring and numerical simulation.The results show that the time-varying curves of contact pressure,reinforcement axial force and concrete stress can be generally divided into construction-disturbed phase,change phase and stabilization phase.The force fluctuation at the invert is larger than that of the sidewall,and it takes longer to reach stability.The contact pressure is unevenly distributed around the circumference,with binaural distribution above the sidewall and dumbbell-shaped distribution at the invert,and the overall contact pressure at the invert is greater than that above the sidewall.The internal force and distribution pattern of secondary lining are significantly different under the theoretical load and measured load.The minimum value of the safety factor is located at the arch crown and both the left and right arch shoulders under the theoretical load,while at the intersection of the invert and sidewall under the measured load.Therefore,the actual force characteristics of secondary lining in sandy loess stratum cannot be properly characterized by the theoretical load based on the loosening pressure.
作者
许泓康
王旭
屈宏录
乔世刚
严松宏
汪精河
XU Hongkang;WANG Xu;QU Honglu;QIAO Shigang;YAN Songhong;WANG Jinghe(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Zhonglan Railway Passenger Dedicated Line Co.Ltd.,Baiyin Gansu 730900,China)
出处
《铁道建筑》
北大核心
2022年第11期112-117,共6页
Railway Engineering
关键词
铁路隧道
二次衬砌
现场测试
数值模拟
受力分析
砂质黄土
安全系数
railway tunnel
secondary lining
field test
numerical simulation
mechaical characteristics
sandy loess
safety factor
