【摘要】 随着城市不断发展，地铁隧道附近开展的施工活动越来越多，基坑开挖引起的地铁隧道产生变形受到更多关注，本文依托杭州市凤起潮鸣项目基坑展开研究，采用Plaxis3D有限元软件，对软土地区坑外土体加固对下卧隧道保护影响进行研究。与实测数据对比后，验证了模型的合理性。研究结果表明，基于土体加固保护措施下，施工前期的土方开挖对隧道隆起变形影响较小，后期土方开挖过程中隧道隆起的速度较快；进行土体加固后，当加固增大到一定强度后，对隧道的保护效果不明显，适宜选用加固强度为0.5 GPa的混凝土。更多还原

【Abstract】 With the continuous development of cities, construction activities near subway tunnels are increasing, and the deformation of subway tunnels caused by foundation pit excavation has attracted more attention. This study is based on the Fengqi Chaoming project foundation pit in Hangzhou, using Plaxis 3D finite element software to investigate the impact of soil reinforcement outside the pit on the protection of underlying tunnels in soft soil areas. The rationality of the model was verified by comparing it with measured data. The research results indicate that under soil reinforcement protection measures, the earthwork excavation in the early stages of construction has a relatively small impact on the heave deformation of the tunnel, while the heave rate of the tunnel increases rapidly during the later stages of earthwork excavation. After soil reinforcement, when the reinforcement strength exceeds a certain level, the protective effect on the tunnel becomes less significant. The most suitable reinforcement strength is determined to be 0.5 GPa concrete.更多还原