震损砌体古塔围箍加固后的滞回特性分析

震损后的古塔结构整体性差,再次受到地震作用后易发生严重破坏甚至倒塌,采用刚性围箍对古塔砌体进行约束增强,可改善古塔砌体的受力性能。为研究受损古塔砌体采用围箍约束后的抗震性能,设计制作了3个古塔子结构模型试件进行拟静力试验,观察了未损试件及其采用角钢围箍约束后的破坏现象,测试了约束后试件的荷载-位移曲线；建立数值模型,计算了模型试件的应力、应变及变形,通过与试验结果对比,分析了约束后古塔砌体的破坏模式,承载力、刚度及延性较震损前的变化关系等。结果表明,刚性围箍装置可有效限制塔体试件在水平荷载作用下的变形和斜裂缝的扩展,提高古塔结构抵抗地震作用的能力,延缓结构刚度退化,骨架曲线的数值计算结果与试验结果一致,角钢围箍与塔体结构的协同工作性能匹配较好,加固效果显著。研究结果可为砖石古塔抗震加固提供参考。

Analysis of Hysteresis Properties of Seismic Damaged Masonry Pagoda Restraint by Rigid Hoops

Due to the weak integrity of the damaged masonry pagodas, it is easily to be destroyed heavily for the pagodas affected by earthquake, even are collapsed. Using rigid hoops to restrain and strengthen the masonry can improve the mechanical properties of ancient masonry pagodas. In order to study the seismic performance of damaged masonry pagoda reinforced with rigid hoop, three sub-structure models of the masonry pagoda were designed and constructed, and the pseudo-static tests were carried out. The damaged specimens and their damage phenomena after reinforcement were observed and tested. The load-displacement curve of the specimen; numerical models were established to calculate the stress, strain and deformation of the ancient pagoda substructure, and the seismic performance index of the reinforced ancient pagoda substructure was obtained through comparative analysis with the test results. As results, the hoop device can effectively confine the horizontal deformation and the expansion of diagonal cracks, improve the ability of the ancient pagoda substructure to resist horizontal deformation, and delay the degradation of structural rigidity. The numerical model can reflect well to the damage of the structure and reinforcement device the characteristics of collaborative work with the structure of the pagoda, and the research results can provide references for the seismic reinforcement of ancient masonry pagoda.