复合地层盾构穿越机场诱发地层沉降计算及控制研究

Construction control and calculation of settlement induced by mixed ground shield undercrossing airport

依托南京轨道交通盾构施工穿越禄口机场段工程,针对上软下硬复合地层盾构施工诱发地层沉降及控制技术进行研究,建立穿越机场前试验段地层沉降初步预测的数值计算模型,通过现场监测数据进行模型参数调整,用于穿越机场时地层沉降的地表沉降的计算;并提出适用于上软下硬复合地层穿越重要建(构)筑物区间的施工控制技术。研究结果表明:隧道横向不均匀沉降影响范围在隧道两侧1.5D范围内;采用"欠土压推进"的模式,穿越重要构筑物区间时地面沉降可控制在允许的范围内。

On the background of shield construction undercrossing Lukou airport section of Nanjing Metro,the settlement induced by control and calculation of shield construction in upper soft and lower hard mixed ground was studied.The numerical model was established for the preliminary forecasting of ground settlement in test sec-tion before shield undercrossing airport.The model parameters were adjusted by site monitoring data,and then, the ground settlement of shield undercrossing airport was calculated.Finally the construction control technology of shield undercrossing important structures interval was proposed in upper soft and lower hard mixed ground. The results show that the influence of transverse differential settlement is in the range of both sides of 1 .5 D of the tunnel.In addition,when shield machinery undercrossing intervals with important structures,the settlement can be controlled within a permissible range by the mode of'under earth pressure'.