为确保地铁盾构下穿古建筑物施工安全，确定先评估、先加固、施工监测、后评估、后加固总体技术路线。通过建立古建筑1：3.52的实体模型并进行振动台试验获取结构阻尼比，利用Ansys进行三维建模，采用结构与模态分析针对易损结构进行加固预防，为后续振动监测与盾构施工提供参考依据，结合试验区施工监测数据，调整施工参数。结果表明，在静力分析下该结构位移最大值约为14.01mm，验证了三维模型的有效性。通过模态分析确定结构模型基本频率为0.59046Hz，最易受损位置为斗枋处。在盾构穿越过程中，古建筑物加速度变化幅度小于0.003m/s2，振动频带主要集中在0.6~20.5Hz，振动频带处于正常范围，对古建筑物基本无影响。针对盾构下穿古建筑物提出以“地铁盾构穿越以匀速掘进为主，避免运营高峰期作业；影响区地层之间使用注浆加固，对古建筑物易损结构进行支护，施工时采取隔振减振方案”的总体解决思路，为后续类似工程建设提供参考。

In order to ensure the safety of subway shield tunneling through ancient buildings, the general technical route of first evaluation, first reinforcement, construction monitoring, later evaluation and later reinforcement is determined. By building a 1:3.52 physical model of ancient buildings and carrying out shaking table tests to obtain the damping ratio of the structure, using Ansys to build a three-dimensional model, using structural and modal analysis for vulnerable structures to strengthen and prevent, it provides a reference for the follow-up vibration monitoring and shield construction, and adjusts the construction parameters according to the construction monitoring data in the test area. The results show that the maximum displacement of the structure is about 14.01mm under static analysis, which verifies the validity of the three-dimensional model. The basic frequency of the structure model is 0.59046Hz, and the most vulnerable position is the sandalwood. In the process of shield tunneling, the acceleration of ancient buildings is less than 0.003m/s2, the vibration frequency is mainly concentrated in 0.6~20.5Hz, and the vibration frequency is in the normal range. The paper puts forward the overall solution of"The subway shield tunneling through the ancient buildings is mainly based on the uniform driving speed, avoiding the operation peak period, using the grouting reinforcement between the strata in the affected area, supporting the vulnerable structure of the ancient buildings, and adopting the vibration isolation and vibration reduction scheme during the construction", for the follow-up of similar projects to provide a reference.

P258

国家自然科学基金项目（面上项目，重点项目，重大项目）