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结合上海地铁11号线侧穿古建筑的实际工程,采用数值计算和现场实测相结合的方法,对国内最新型的MJS桩基施工预加固与新建隧道侧穿引起的邻近古建筑的沉降进行了深入研究。整个施工力学的全过程对建筑物的影响分为桩基施工扰动阶段、上行线穿越阶段和下行线穿越阶段3个阶段。其中先期桩基施工扰动的影响相对显著,但由于MJS桩的保护作用,上行线穿越影响次之,下行线穿越影响最小。计算结果表明,由于桩基施工的预加固与隧道左侧建筑物的存在,使得地表的沉降槽与传统的形式有较大区别;同时,地表的水平位移分布规律也发生了明显的变化。此外,由于隔离桩的保护,大大减少了盾构掘进对地表以及建筑物沉降的影响。现场监测与数值计算的结果对比分析也表明两者所反映的规律较一致,其数值差别较小,进而验证了数值计算方法的准确性与合理性。
Combined with the actual engineering of the side-penetrating ancient buildings on line 11 of Shanghai Metro, the method of combining the numerical calculation and on-site measurement was applied to analyze the settlement of the nearest ancient MJS pile foundation construction pre-reinforcement and the adjacent ancient buildings caused by the new tunnel side- In-depth study. The whole process of construction mechanics impact on the building is divided into pile construction disturbance phase, the upward line through the stage and the downlink through the stage three stages. Among them, the influence of pre-construction pile disturbance is relatively obvious, but due to the protective effect of MJS pile, the upward crossing crosses the second, and the downward crossing crosses the least. The results show that due to the pre-reinforcement of the pile foundation construction and the existence of the left buildings on the left side of the tunnel, the settlement grooves on the ground surface are greatly different from the traditional forms; meanwhile, the horizontal displacement distribution pattern of the ground surface also changes obviously. In addition, due to the isolation piles, the impact of shield tunneling on the ground surface and the settlement of buildings is greatly reduced. The comparative analysis of the results of on-site monitoring and numerical calculation also shows that the laws reflected by both are consistent and the difference of numerical values is small, which proves the accuracy and rationality of the numerical calculation method.