围岩蠕变对隧道下穿建筑物施工变形的影响

为研究考虑岩体蠕变时隧道下穿建筑物施工引起围岩和建筑物的变形规律及特点,结合同茂隧道下穿地表复杂建筑群的工程实践,以隧道下穿6号楼为例,分别进行了围岩弹塑性和考虑其蠕变的粘弹塑性数值模拟研究。对比分析两种计算结果发现,岩体蠕变显著增大了建筑物桩基础的沉降和水平位移,并改变了桩基础的沉降曲线形态和水平位移规律,进而改变了桩基础连梁的受力特征。此外,岩体蠕变扩大了上覆建筑物荷载对隧道的影响范围,改变了桩基础周围岩体塑性区的分布。

Influence of Surrounding Rock Creep on the Construction Deformation of Tunnel Undercrossing Buildings

In order to study the regularity and characteristics of construction deformation of surrounding rock and buildings caused by tunnel construction undercrossing buildings considering the influence of the rock mass creep, the elastic-plastic numerical simulation and the viscous elastic-plastic numerical simulation are conducted respectively. The simulation is based on the practice of Tongmao Tunnel going through complex building blocks under the ground and the building No.6 is chosen as the research case. It is found that rock mass creep may not only amplify the settlement and horizontal displacement of the pile foundation significantly, but also alter the settlement curve shape and the regularity of the horizontal displacement of the pile foundation. Accordingly, the mechanical characteristics of the coupling beams of the pile foundation change with the time slowly. Furthermore, the rock mass creep can enlarge the region in which the load of the overlying buildings influences the tunnel evidently and it may lead to the change of the distribution of the plastic zone around the pile foundation.