复杂地质条件下盾构切削建筑物桩基群影响分析

Analysis of Influence of Shield Tunnel Cutting Building Pile Foundation Groups under Complicated Geological Conditions

结合广州地铁盾构隧道切削桩基下穿办公楼的工程实例,采用三维模型对复杂地质条件下盾构切桩前、切桩过程、下穿完成全过程办公楼沉降及变形响应进行有限元分析,并对比盾构下穿全过程现场实测数据。结果表明:盾构切桩下穿办公楼过程沉降及变形在规范允许范围内,不会影响建筑物的正常使用;在盾构下穿过程后,建筑物会持续沉降约20天,沉降值较小。建议管片设计计算桩端荷载时考虑桩侧摩阻力受盾构影响的损失,以保证管片结构及建筑物的安全。

With the engineering example of the cutting pile foundation of the Guangzhou Metro shield tunnel passing through office building,three-dimensional models are adopted to conduct finite element analysis on the settlement and deformation responses of the office building during the whole process of the shield cutting pile(before,during and after pile cutting)under complex geological conditions,and the results are then compared with the field test data.Research results indicate that,the settlement and deformation of the shield cutting piles under the office building are within the allowable range,which will not affect the normal use of the buildings.After the shield tunneling is completed,the settlement of the building will last for about 20 days,with small settlement value.It is suggested that the loss of pile side friction affected by shield should be taken into account when calculating the pile end load in the segment design,in order to ensure the safety of both segment structures and buildings.