重叠隧道施工数值分析

以佛山地铁莲塘-张槎盾构区间重叠隧道为工程依托,运用MIDAS/GTS有限元程序模拟盾构开挖的全过程,采用不加固和地面加固两种施工工况,分析不同工况下重叠隧道施工对地表沉降和盾构管片内力影响,结果表明:地层受盾构施工的影响范围都逐步扩展,地表沉降曲线符合Peck沉降槽规律。地面加固后地表最大沉降量约为18.8mm,未加固地表最大沉降量约为102.3mm。洞内注浆加固后能够减小盾构管片内力。

NUMERICAL SIMULATION OF OVERLAPPED SHIELD-DRIVEN TUNNELING

The paper took the overlapped Shield tunnel in the Metro from Liantang to Zhangcha in Foshan as an example.MIDAS / GTS dimensional finite element software was used to simulate the entire process of shield excavation.This engineering case had two types of construction conditions,i.e.,the grounds with and without reinforcement,so the effects of the overlapping tunnel construction on the ground settlement and the internal force of shield segment were analyzed under these two types of construction conditions.The results shows that the region of the ground affected by overlapping tunnel construction extends gradually,and the settlement curve of the ground accords with Peck sedimentation tank law.The maximum values of the ground settlement with and without the reinforcement are about 18.8 mm and 102.3rm,respectively.The grouting reinforcement can effectively reduce the internal force of shield segment.