基于三维离散单元法庞贝古城柱廊的动力特性分析

Seismic responses of Pompeii colonnade structure based on three-dimensional distinct element method

为探索意大利庞贝古城双层柱廊结构的地震动力响应,建立了一个典型的双层柱廊结构的三维实体模型,并用三维离散元程序3DEC对柱廊结构进行了地震动力模拟计算,分析了简谐波及实测地震波的频率、加速度幅值及荷载施加方向等对柱廊结构稳定性的影响规律.数值模拟结果表明：在简谐波作用下,柱廊结构的变形随着加速度幅值的增加而变大,低频波比高频波更容易导致柱廊结构发生破坏,位移较大的部位出现在横梁和下层石柱,横梁可以削弱向上传播的动力荷载,柱廊结构在平面外方向的抗震能力低于平面内方向.

The seismic responses of a two-story colonnade of the Forum in Pompeii are investigated in a three-dimensional discrete element model built on the distinct element method（DEM）code 3 DEC.Both artificial harmonic and real earthquake waves are experimented in this study.The sensitivity of the dynamic response of the colonnade to the frequency and acceleration magnitude of the input motions is analyzed.The simulation results show that a loading wave with greater acceleration amplitude will lead to a larger deformation;ground motions with low-frequency wave components are more destructive to the colonnade than those with higher frequency;and the colonnade can collapse more easily in the out-of-plane direction.