关于地铁保护区近距离桩基施工技术的探讨

Discussion on Construction Technology of Piles Close to Subways Protected Area

随着城市建设的发展,地铁保护区内桩基施工越来越多,国内多次发生桩基施工损坏地铁隧道结构和影响运营事件,应充分认识施工中地铁保护的重要性和迫切性。针对成都地区受盾构扰动、超挖及降水影响的砂卵石地层,深入分析地铁保护区内近距离桩基施工对既有隧道结构影响,根据实际情况介绍了护筒跟进施工工艺,提出了上挖下钻变径施工工艺。

With the development of urban construction,more and more piles are constructed in the controlled and protected area of subway.Several events have happened that the pile construction damages the subway tunnel structure and affects the operation.The importance and urgency of subway protection in pile construction should be fully recognized.For the sandpebble strata in Chengdu area is affected by shield disturbance,over-excavation and precipitation,the analysis is carried out in the influence of the near-distance pile construction in the subway protection area on the existing tunnel structure.According to the actual situation,the construction technology of the casing is followed up,and the construction technology of the excavating-above-and-drilling-below variable diameter construction process is proposed,providing reference for similar pile foundation construction.