基坑群开挖对近接运营地铁隧道隆沉变形的影响研究  

Study on Effects of Group Foundation Pits Excavation on Heaving/Settlement of Adjacent Metro Tunnel in Operation

作　　者：刘继强[1,2] 欧雪峰[3] 张学民[3] 梁青槐[1] 阳军生[3] 刘学勤 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中铁建设投资集团有限公司,深圳518055 [3]中南大学土木工程学院,长沙410075

出　　处：《现代隧道技术》2014年第4期81-87,120,共8页Modern Tunnelling Technology

基　　金：中国中铁股份有限公司科技开发计划重点课题(2012-19);国家自然科学基金项目(51378505);"十二五"国家科技支撑计划课题(2012BAK24802)

摘　　要：文章以深圳地铁车公庙枢纽工程为例,研究了受基坑群开挖影响的近接运营地铁隧道的隆沉变形规律及其变位控制措施。为了达到控制既有隧道及轨道结构变位的目的,通过方案优化、理论分析和数值模拟等研究手段,根据结构变位分配原理,制定了基坑群施工各步序轨道结构的变形控制标准。受基坑开挖卸载效应的影响,近接既有隧道具有明显的变位叠加效应,其中基坑开挖卸载和降水是影响结构变形控制的关键步序。基坑降水对控制下卧隧道隆起变形是有利因素,但紧邻侧方位基坑降水对控制结构水平变形是不利因素,因此在设计和施工中应综合考虑地下结构不同方向变位基准来制定合理的降水措施。实测结果表明,基坑群开挖过程中既有地铁轨道结构变形满足控制标准要求,验证了变形控制基准的合理性和工程措施的有效性。The Che Kung Temple interchange project of Shenzhen Metro is used as an example in this paper to study the heaving/settlement laws and the displacement control measures for the adjacent metro tunnel in operation which is effected by excavation of group foundation pits. In order to control the displacement of existing tunnel and track structure, the deformation control standards for track structure in each construction step of group foundation pits are set by means of scheme optimization, theoretical analysis and numerical simulation based on the distribution principle of structure displacement. With the unloading effect induced by foundation pit excavation, the displacement superimposed effect of adjacent existing tunnel is noticeable, therefore the excavation and dewatering of the pit are the key steps among the construction sequence of group foundation pits. Foundation pit dewatering is a favorable factor for controlling the heaving of underneath tunnel, while it is an unfavorable factor for controlling the horizontal deformation. Consequently, the displacement reference values of the underground structure in different orientations shall be taken into account as for the reasonable dewatering measures in the progress of design and construction. The actual measurements show that during the excavation of group foundation pits, deformation of existing subway structure is not beyond the specific standard, the deformation control standards are reasonable and the engineering measures are effective.

关 键 词：基坑开挖 既有地铁隧道 变形控制 现场监测 数值模拟 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]