基坑群施工对邻近隧道影响与隧道保护

通过对邻近隧道基坑群分布类型进行分类归纳,系统研究了不同分布类型基坑群施工对邻近隧道的影响,揭示了各影响因素的作用机制,并提出了相应的保护措施,可为邻近隧道基坑群施工和隧道保护提供理论支撑.根据基坑群与邻近隧道位置关系可将基坑群分为单侧坑和双侧坑,根据基坑群单坑开挖深度和共墙情况可将基坑群分为邻近坑、贴靠坑和坑中坑,不同类型基坑对隧道的影响各不相同.基坑群施工对隧道的影响有"时空效应"、土压力多次卸荷、土体变形叠加效应、地下水影响等诸多方面.为控制基坑群施工对隧道的影响,可以在基坑群施工中采取合理分区分块、合理安排施工顺序,针对性调整围护结构刚度并采取适当加固,制定合适的降水方案和信息化施工等措施,以确保施工和隧道安全.最后结合上海龙华航空中心工程,采用数值分析和现场监测方法,阐述了基坑群施工中各影响因素的作用机制,并验证了各工程措施的有效性,可为预测、分析基坑群施工对邻近隧道影响,保护隧道结构提供参考.

Adjacent Tunnels and Tunnel Protection

bstract： The influence of different distribution types of excavation adjacent to tunnels was studied systematically by classification and induction of the distribution types of excavation. The action mechanism of the effects was revealed and the corresponding protective measures was proposed to provide the theoretical support for the excavation construction and protection of the adjacent tunnels. According to the position relationship between the excavation and the adjacent tunnels, the excavation can be divided into two groups, one side excavation and two side excavation. According to the excavation depth and the sharing of retaining structure, the excavation can be divided into near excavation, close excavation and excavation in excavation. The influence of excavation on the adjacent tunnels can be summarized as space time effect, earth pressure multiple unloading, soil deformation superposition effect, groundwater influence and so on. To control the influence of excavation on adjacent tunnels, some measures can be taken such as reasonable partition, reasonable arrangement of construction sequence, adjustment of structural stiffness and reinforcement. Finally, the project of Longhua Aviation Center in Shanghai was analyzed in detail by using the numerical analysis method and field monitoring method which can provide reference for other projects of excavation group construction and tunnel protection.