通海台垂直摆受建筑载荷影响的数值模拟研究

针对通海台垂直摆NS和EW测项自2019-04出现同步趋势转折变化，计算2017~2020年NS和EW测项M₂波潮汐因子。结合监测井等地下介质结构资料，构建通海台沿垂向分层的三维有限元物理模型，定量分析不同岩石参数模型下建筑载荷对通海台NS向及EW向位移影响的差异特征。结果表明：1）2019-04后NS测项N倾变化量达到约2 750 ms，而EW测项E倾变化量达到约580 ms，NS测项趋势变化量显著大于EW测项；2）2017~2020年NS和EW测项M₂波潮汐因子较为稳定，NS测项M₂波潮汐因子在0.7左右波动，EW测项M₂波潮汐因子在0.52左右波动，数据的转折变化未能在潮汐频段引起同步变化；3）位于通海台东北部的医院建筑物载荷在通海台附近产生N向和E向位移加载，与垂直摆NS和EW测项在2019-04后出现的N倾和E倾趋势转折变化较为一致，模拟得到的N向位移量约为E向位移量的3倍。

Study on Numerical Simulation of the Vertical Pendulum of Tonghai Station Influenced by Building Loads

In view of the synchronous trend change of NS and EWcomponents of Tonghai vertical pendulum since April 2019, we calculate the M₂ wave tidal factor of NS and EW components from 2017 to 2020. Combined with the structural data of underground media such as monitoring wells, we construct three-dimensional finite element physical models of vertical stratification of Tonghai station. We quantitatively analyze the differential characteristics of the influence of building load on NS and EW displacement under different rock parameter models. The results show that: 1) Since April 2019, the N-tilt variation of NS component reaches about 2 750 ms, while the E-tilt variation of EW component reaches about 580 ms. The trend variation of NS component is significantly bigger than that of EW component. 2) From 2017 to 2020, the M₂ wave tidal factor of NS and EW components are relatively stable, in which the NS component fluctuates around 0.7 and the EW component fluctuates around 0.52. The trend break of data fails to cause synchronous change in the tidal frequency band. 3) The hospital building load located in the northeast of Tonghai station generates N-direction and E-direction displacement, which is consistent with the N-tilt and E-tilt trend break of vertical pendulum after April 2019. The simulated N-tilt displacement is about 3 times of E-tilt displacement.