三轴深层搅拌桩加固盾构端头施工技术研究

Research on Construction Technology of Tri-axial Deep Stirring Piles in Reinforcing Soil Mass at Shield End

以南京地铁9号线滨江公园车站盾构端头加固工程项目为背景,对长江漫滩复杂地层条件下三轴水泥搅拌桩施工工艺进行研究。为提高施工质量和施工效率,减少施工对周边建筑物的影响,提出采用两喷两搅的施工工艺,跳打的施工顺序。通过钻心取样观测和强度检测,及端头盾构施工地表沉降观测,结果表明,对于长江漫滩地层三轴搅拌桩采用两喷两搅工艺和跳打施工顺序,能够有效保证搅拌桩的施工质量,确保地铁车站盾构端头加固效果。

Based on the shield end reinforcement project of Binjiang Park Station of Nanjing Metro Line 9,the construction technology of tri-axial cement mixing pile in the Yangtze River floodplain with complex stratum is studied. In order to improve the construction quality and efficiency and reduce the impact of construction on surrounding buildings, the construction process of“two sprays and two mixes”and the construction sequence of “skip beating”are proposed. Through the observation of core drilling sampling and strength testing,as well as the observation of the surface settlement of the end shield construction, the results show that the use of the two spraying and two mixing process and the skip driving construction sequence for the three-axis mixing pile in the Yangtze River floodplain stratum can effectively ensure the construction quality of the mixing pile and the reinforcement effect of the shield end of the subway station.