基于Pushover分析的砖石古塔抗震性能评估

Evaluation of seismic performance of ancient masonry towers based on Pushover analysis

砖石古塔自重大、材料强度低,在地震时极易受损。为了研究砖石古塔在地震作用下的抗震性能,利用Abaqus有限元软件建立了砖石古塔三维数值模型,并对模型合理性进行检验,利用Pushover方法,以最大层间位移角为评判指标,对砖石古塔的抗震性能进行评估,进一步模拟了地震作用下砖石古塔的损伤演化过程。结果表明:数值模型动力特性与实测结果接近,模型较为合理;当小震发生时,结构发生轻微破坏,当中震和大震发生时,结果发生严重破坏;地震时结构东西侧面的破坏以形成弯拉水平裂缝为主,南北侧面洞口处出现剪切斜裂缝,各层斜裂缝逐步相接形成贯通裂缝;模拟结果与实际震害基本一致。

Ancient masonry towers are self-heavy and have low material strength,and are easily damaged during an earthquake.In order to study the seismic performance of ancient masonry towers under earthquake action,a three-dimensional numerical model of ancient masonry towers was established using Abaqus finite element software,and the rationality of the model was tested.The Pushover method is used to evaluate the seismic performance of ancient masonry towers with the maximum displacement angle between floors as the evaluation index,and the damage evolution process of ancient masonry towers under earthquake action is further simulated.The results show that the dynamic characteristics of the numerical model are close to the measured results,and the model is reasonable;When a small earthquake occurs,the structure is slightly damaged,and when a moderate and large earthquake occurs,the result is severe damage;During the earthquake,the damage to the east and west sides of the structure was dominated by the formation of bending and tension horizontal cracks.Shear oblique cracks appeared at the openings on the north and south sides of the structure.The oblique cracks of each layer gradually connected to form through cracks.The simulation results with the actual damage is more consistent.