地铁盾构施工会使周边临近构筑物产生不均匀沉降和倾斜,对构筑物结构的稳定性产生不良影响.北京地铁某盾构区间近距离下穿铁路通信发射塔一年后,经检测发现发射塔基础产生了较大不均匀沉降.基于该铁路通信发射塔,结合工前、工后(施工1年后)检测结果及施工过程监测数据,采用有限元数值模拟分析方法,考虑地铁盾构施工造成的结构不均匀沉降及结构初始差异沉降,综合分析盾构近距离施工对通信发射塔结构稳定性的影响,评价通信发射塔的安全状况.研究表明:盾构隧道施工所产生的不均匀沉降造成的通信发射塔结构变形在安全容许范围内,结构变形均能满足发射塔材料安全性要求,通信发射塔基础东北角与东南角塔基承载力安全系数较低,需对其采取加固措施.%Metro shield construction can cause differential settlements and inclination on adjacent structures, which will take negative influence on the structure stability. When a certain shield zone of Beijing metro(subway) close undcrcrossed communication tower a year later, the tower foundation had have larger differential settlements by on-site inspection. Combining inspection results of before-con-struction and post-construction (one year after construction) with monitoring data during construction, this paper used the finite element method to analysis the impact on structural stability of the communication tower caused by metro shield construction and assessed the safe condition of the communication tower. These are all based on the structure differential settlements caused by metro shield construction and the initial structure settlements. The results show that the range of structure deformation of the communication tower caused by differential settlements of shield construction is in a safe allowable range. The structure deformations can meet the safety requirements of the tower materials. But bearing capacity safety coefficients of northeast corner and southeast corner on the foundation of communication tower are lower, which need some reinforcement measures.
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