将隧道、地基和上部结构作为一个整体开展系统研究,既分析了下穿隧道对建筑沉降和局部内力增加的影响,又分析了隧道开挖后对建筑抗浮的影响,并提出了相应的工程措施:通过加密初支钢架和施工优化来控制沉降,通过将抗浮锚杆及时与隧道内钢架焊接来恢复抗浮力。后期现场施工监测结果表明:数值计算对建筑沉降的预估是合理的,强化支护和施工优化对沉降的控制是明显的,对建筑抗浮能力丧失的补救措施是有效的。
The behavior of a tunnel and the underground structure above it are considered as an integral system in this paper. The effect of the tunnel underpass excavation on the ground settlement as well as the stress in the above underground structure is analyzed. The mitigations of the ground settlement and the increased buoyancy induced by the tunnel excavation are also presented in the paper. The induced ground settlement can be minimized by the increased steel support frames and through the construction optimization. The increased buoyancy can be counterbalanced by the ground anchors that welded to the steel support frames. The construction monitoring results indicate that the numerical analysis predicted ground settlement magnitude is reasonable and the increased supporting frames and the optimized construction have a significant impact on the ground settle ment reduction. The ground anchors can improve the buoyancy capacity of the underground structure.