应县木塔精细化结构建模及水平受力性能分析

Lateral structural performance of Yingxian Wood Pagoda based on refined FE models

结合现场调查,对应县木塔进行结构体系分析、精细化建模、动力特性和水平受力性能分析。分析表明,应县木塔为"层叠平台式梁柱结构"体系。使用梁-短柱单元组模拟斗栱,刚度等效单元模拟梁柱及柱脚节点,建立了木塔的理想和现状精细化模型进行分析。结果表明,土磬墙对第1明层有嵌固作用,故木塔第1层侧移呈弯曲型而其它各层主要呈剪切型;明层铺作、暗层柱架、暗层铺作和明层柱架的抗侧移刚度依次减少,现状模型抗侧移刚度比理想模型平均低33%;多遇地震作用下,木塔部分明层柱架侧移角超过了弹性层间位移角限值;基于木塔柱脚连接特点,提出使用"重力抗倾覆力矩与倾覆力矩之比"作为木塔倾覆评判准则,多遇地震作用下木塔无倾覆危险,但在罕遇地震作用下则可能倾覆。

This paper presents the structural system analysis, refined FE modelling, dynamic characteristics and lateral structural performance analysis of Yingxian Wood Pagoda. The pagoda can be regarded as a layered platform beam-column structure. Two refined FE models of the structure of Yingxian Wood Pagoda with and without considering damage were developed based on ABAQUS platform, respectively, in which the Dou-Gong was modeled with beam- short-column assembly and the column-frame joints were simulated with stiffness-equivalent elements. The lateral drift of the ! st story of the pagoda appeared as bending type while those of other stories showed as shearing type, since the mud wall strengthened the column frames of the 1 st story. The lateral stiffness of the Pu-zuo layers in the apparent stories, the column-frames in hidden stories, the Pu-zuo layers in hidden stories and the column-frames in exposed stories decreased, sequentially. The lateral stiffness of the pagoda lower than those of the pagoda model without considering damage ratios of several apparent stories exceed the elastic inter-story drift of the pagoda was suggested, and the safety of Yingxian Yingxian Wood Pagoda has not overturned under the frequent earthquake, there is still potential in some level to overturn under rare earthquake.