盾构隧道下穿人行天桥桩基处理技术

武汉轨道交通4号线某区间盾构隧道穿越人行天桥桩基。在盾构穿越天桥前,必须清除隧道开挖范围内的桩基。在无交通疏解和工期紧的条件下,首先搭设临时支架保护天桥,从地面注浆加固土体,在托换承台后,人工挖竖井从竖井中凿除盾构隧道范围内桩基,同时盾构穿越时调整施工参数。整个施工过程中,天桥正常通行,盾构穿越天桥后,承台最大累计沉降在3mm以内,保证了天桥的安全和盾构施工工期,到达了预期效果。

Pile Foundation Treatment Technology of Shield Tunnel beneath Footbridge

Line 4 of Wuhan urban rail transit uses shield tunneling across the pedestrian bridge with pile foundation. Before the shielding crossing the footbridge, piles within tunnel excavation region must be cleared. Under heavy traffic without diversion and with a fight project schedule, temporary support to protect the footbridge is erected, with grouting reinforcing soil from the ground. ARer supporting and changing the abutment, manual shaft dug from the existing shaft to remove pile foundation in the shield tunnel. At the same time shield adjusts construction parameters while tunneling. Throughout the construction process, the footbridge functions as normal passage. After shield crosses the footbridge, the maximum cumulative settlement of the abutment is less than 3 ram, the footbridge safety and shield construction period are ensured, reaching the expected results.