实心结构古塔模型频域地震响应试验研究

为研究地震作用下实心结构砖石古塔的频域地震响应与破坏机制,进行了兴教寺玄奘塔1/8比例模型振动台试验,观察结构的破坏特征,测试结构的加速度与位移反应并分析自振频率的变化特征,对比单向EL-Centro波与天津波作用下的加速度及位移频域响应曲线,分析了古塔结构频域地震响应的规律及其影响因素。结果表明:地震波激励下古塔结构模型第1层至第3层出现水平及斜向裂缝,当古塔结构发生地震损伤后,自振频率随之降低;古塔频域地震响应峰值的分布及其所对应的频率与结构的动力特性、地震波的频谱特性有关。因此,地震作用下实心砖石古塔结构频域地震响应与结构损伤程度密切相关。

Tests for frequency domain seismic responses of masonry pagoda with solid structure

In order to study frequency domain seismic responses and failure mechanism of masonry pagoda with solid structure under earthquake, shake table tests were conducted for the model with scale of 1/8 for Xuanzang Pagoda in Xingjiao Temple. Failure characteristics of the model structure were observed. The structure’s acceleration and displacement responses were measured, and its natural frequencies’ variation characteristics were analyzed. Its frequency domain acceleration and displacement response curves under El-Centro wave in a single direction were compared to those under Tianjin one in the same direction to analyze laws of the pagoda’s frequency domain seismic responses and their affecting factors. The results showed that horizontal and oblique cracks appear in the pagoda model’s 1st^3rd floors under seismic waves;after the pagoda has seismic damages, its natural frequencies drop;the peak value distribution of its frequency domain seismic responses and the corresponding frequency are related to its structure dynamic characteristics and seismic waves’ spectral features, so the pagoda’s frequency domain seismic responses are closely related to its structure’s damage level.