摘要
随着城市地下空间的进一步开发利用,盾构隧道埋深不断增加,合理确定深埋盾构隧道上方的垂直土压力是合理进行管片设计的关键。随着隧道埋深增加,土拱效应明显,深埋隧道上方会形成稳定的松动区。利用离散元软件PFC2D对深埋盾构隧道在砂土中的开挖进行数值模拟,通过观察隧道上方松动区形状,对TERZAGHI松动土压力计算公式进行改进,提出砂土中深埋隧道上方松动土压力的计算方法。结果表明:与TERZAGHI理论假定的直立滑动面不同,深埋盾构隧道松动区为三角形;松动区滑动面上的侧压力系数大于TERZAGHI的建议值。通过与现场实测数据进行对比分析,验证了该公式的合理性,该成果可用于深埋盾构隧道的垂直土压力计算。
With the development and utilization of urban underground space,deep buried shield tunnels get more and more popular.How to determine the vertical earth pressure above deep buried shield tunnel is the key issue for reasonable segment design.With the increase of tunnel depth,the soil arch effect is increased and the disturbed zone will be formed above the tunnel.Numerical investigation of the excavation of deep buried tunnel in sand was carried out using PFC2D to observe the shape of the disturbed zone above the tunnel.Based on it,a modified failure mechanism of TERZAGHI was improved and a new computing method of vertical earth pressure above deep buried tunnel in sand was proposed.The results showed that the disturbed zone was triangular,the sliding surface was not vertical which was assumed by TERZAGHI.The lateral pressure coefficient of the sliding surface was larger than the suggested value of TERZAGHI.Finally,the results of the proposed method was verified using the field observed data.The proposed method can be used to analyze the vertical earth pressure above deep buried tunnel.
作者
刘宏达
杨天亮
张冬梅
LIU Hongda;YANG Tianliang;ZHANG Dongmei(Key Laboratory of Geotechnical and Underground Engineering of Minister of Education,Shanghai 200092,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Land Subsidence Monitoring and Prevention,Ministry of Natural Resources,Shanghai Institute of Geological Survey,Shanghai 200072,China)
出处
《隧道与地下工程灾害防治》
2020年第2期31-40,共10页
Hazard Control in Tunnelling and Underground Engineering
基金
国家自然科学基金资助项目(41772295)。
关键词
深埋隧道
垂直土压力
砂土
离散元
deep buried tunnel
vertical earth pressure
sand
discrete element method
