摘要
以扬州瘦西湖隧道为工程依托,对超大直径盾构隧道管片荷载、结构内力等进行长期现场监测,分析超大直径浅埋盾构隧道土压力、管片钢筋应变的变化规律。采用上覆土柱法、太沙基松弛土压力法计算管片土压力理论计算值,并与现场实测结果对比,分析不同土压力计算方法在不同埋深条件下的适用范围。结果表明,盾构纠偏对隧道管片荷载大小、分布形式影响较大,且其影响一致持续至稳定期;盾构隧道施工结束后,作用在盾构管片上的土压力逐渐减小并趋于稳定;管片钢筋应变同土压力变化趋势基本一致,但进入稳定期时间略滞后于土压力,土压力进入稳定期后实测土压力值约为理论计算值的48%~60%;松弛土压力法计算的土压力值较上覆土柱法计算值和实测结果更为接近。研究成果可为盾构隧道管片设计荷载取值提供指导。
Based on the Yangzhou Shouxi lake tunnel,the load of segments and structural strain etc of shallow buried shield tunnels with super-large diameters were constantly monitored in the field.Variation rules of earth pressure,and the strain of steel bar were analyzed.Then,the theoretical earth pressures at the segment of the tunnel were calculated based on the overburden load method and Terzaghi’s earth pressure method.These theoretical results were compared with the measurement values,analyzing the applicability of different earth pressure calculation methods under different buried depths.The results show that shield rectification has a great impact on the value of tunnel segment load and its spatial distribution,and the impacts lasts until the stability period.The earth pressure on shield segments decreases and tends to be stable gradually after the construction of shield tunnel.The change trend of steel bars’strain is basically the same as the earth pressure,but the former lags behind the latter for reaching the stable state.When the earth pressure reaches the stable state,the measured value is about 48%-60%of the theoretical value.The earth pressure value calculated by the Terzaghi’s earth pressure method is much closer to the measured value than that of the overburden load method.Thus,the study in this paper can provide guidance for the load design of shield tunnel segments.
作者
章定文
刘志祥
沈国根
鄂俊宇
ZHANG Ding-wen;LIUZhi-xiang;SHENGuo-gen;E Jun-yu(School of Transportation,Southeast University,Nanjing,Jiangsu210096,China;Tunnel Management Office of Yangzhou,Yangzhou,Jiangsu225002,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第A01期91-98,共8页
Rock and Soil Mechanics
基金
江苏省建设系统科技项目（No.2016ZD70）~~
关键词
超大直径浅埋盾构隧道
土压力
现场监测
理论计算方法
super-large diameter and shallow shield tunnel
earth pressure
field monitoring
theoretical calculation methods
