盾构隧道下穿软弱土层既有人行天桥桩基设计探讨

地铁盾构隧道下穿软弱土层既有人行天桥钢筋混凝土桩基,设计中采用扩大基础对人行天桥桩基进行被动托换,同时在有限的桥下空间采用松木桩加固扩大基础底部软弱土层,结合加强盾构管片配筋、设置地面临时托换支架等措施,确保盾构机直接切削桩基通过后,地面天桥满足正常使用条件、高含筋量混凝土管片的强度及刚度均满足要求.该综合处理方式避免...

Discussion on Design of Shield Tunneling under Pile Foundation of Existing Footbridge in Weak Soil Layer

Subway shield machine cut across concrete pile of footbridge in weak soil,it is necessary?to clear the pile foundation within the tunnel, and to ensure the normal use of the pedestrian bridge.In the design, the pile foundation of footbridge is replaced by expanding the foundation, the soft ground is strengthened, the concrete segment is strengthened, and bracket for underpinning uses.After the shield machine cuts the pile ,footbridge meets the requirements of normal use,and the force and deformation of the concrete segment meet the requirements.The method avoids the demolition and secondary construction of the footbridge, and has great economic and social benefits, and provides a good reference for similar projects.