摘要
[目的]隧道侧穿或下穿高架桥的施工情况及相关研究越来越多,但是对于双隧道下穿临近高架桥且以粉土为主要成分地质条件的案例研究较少。[方法]本研究以深圳地铁7号线西丽~珠光(DK2+420~DK5+190)段盾构区间下穿高速高架桥为背景,建立三维数值计算模型对墩顶位移和离隧道最近桩节点位移变化进行分析研究。[结果]研究表明:墩顶横向位移在先行隧道贯通前逐渐增大,但随着后行隧道的开挖,桩基两侧的土体产生的土压力逐渐平衡,墩顶横向位移逐渐减小,向初始位置靠近;墩顶纵向位移随着隧道开挖逐渐增大,位移方向同盾构掘进方向相反;墩顶竖向位移随着盾构掘进逐渐增大;双隧道两侧桥桩横向位移随着隧道的开挖和墩顶力的共同作用,位移逐渐增大,左右线贯通后达到最大值,但双隧道中间桥桩随着右侧隧道掘进,由于两侧土体产生的土压力逐渐平衡,横向位移逐渐减小,向初始位置靠近。[结论]下穿邻近高架桥的粉土地层的地铁隧道,应根据其工程变形规律,避免对既有工程造成影响,本研究对于同类型工程设计和研究具有一定参考。
[Purposes]There are more and more studies on the construction of tunnels passing sideways or under viaducts and related to them,but there are fewer case studies on the geological conditions of double tunnels passing under adjacent viaducts and with powder soil as the main component.[Methods]In this article,a three-dimensional numerical calculation model is established to analyze and study the displacement changes of pier top and nearest pile nodes from the tunnel in the context of shield interval underpassing a high-speed viaduct in the Xili~Zhuguang(DK2+420~DK5+190)section of Shenzhen Metro Line 7.[Findings]The results show that:the transverse displacement of the top of the pier gradually increases before the first tunnel is opened,but with the excavation of the later tunnel,the earth pressure generated by the soil on both sides of the pile foundation is gradually balanced,and the transverse displacement of the top of the pier gradually decreases and approaches to the initial position;the longitudinal displacement of the top of the pier gradually increases with the excavation of the tunnel,and the displacement direction is opposite to that of the shield tunneling;the vertical displacement of the top of the pier gradually becomes larger with the shield tunneling;the transverse displacement of the bridge piles on both sides of the double tunnel The displacement gradually increases with the excavation of the tunnel and the joint action of the pier top force,and reaches the maximum value after the left and right lines are passed,but the middle bridge pile of the double tunnel gradually decreases with the right tunnel excavation due to the gradual balance of the earth pressure generated by the soil on both sides,and the lateral displacement approaches the initial position.[Conclusions]In this study,a three-dimensional numerical calculation model is established to investigate the deformation of the pile foundation of an adjacent viaduct under an underpass interval tunnel with powder soil as the main geological condition,to provide some reference value for the design and research of the same type of project.
作者
罗劲
LUO Jing(College of Geosciences and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450000,China)
出处
《河南科技》
2023年第9期79-83,共5页
Henan Science and Technology
关键词
区间隧道
邻近高架
桩基础
位移
interval tunnel
near the viaduct
pile foundation
displacement
