窑洞外形特征对结构抗震性能影响研究
Effect of Cave Dwelling Shape on the SeismicPerformance of Structures

调查发现山西北部农村地区农居窑洞多是独立式土坯窑洞，结构主要受力体系是土坯砌体砌筑拱结构，其建造统一标准，外形样式存在差异。由于拱结构的内力分布对外形尺寸变化比较敏感，为研究窑洞外形特征对结构抗震性能影响，建立相应的有限元模型进行计算分析，对比不同外形特征窑洞在地震作用下的损伤情况，并结合历史震害，指出窑洞结构的薄弱位置。研究结果表明覆土较厚的窑洞容易损伤，连拱孔数较多窑洞的两侧位置更容易发生破坏，拱的曲线形状对结构抗震性能有一定影响，合理拱曲线窑洞的抗震性能优于一般形状窑洞。
Through several earthquake damage investigations, it has been found that the casualties and economic losses during earthquakes are mainly caused by the building damage. Buildings in rural areas should be given more attention as they are mostly substandard, and hence, would have poor seismic performance. As a kind of green building structure system, cave structures have the advantages convenience, simple construction, low cost, and thermal insulation, so they are widely used in rural areas. Through the investigation of cave dwellings in the rural areas of northern Shanxi, it is concluded that most cave dwellings are independent adobe caves, where the predominant system is the adobe masonry structure, and there is no unified standard of cave construction, which leads to differences in shapes. As the internal force distribution of an arch structure is sensitive to change in shapes, to study the influence of shape characteristics of a cave on its seismic performance, a finite element model is established and analyzed. Combined with historical seismic disasters of caves, the damages of caves with different shape characteristics under earthquakes were compared. The results show that caves with thicker overburdened soil are more fragile, and two sides of a multi-span cave dwelling are more vulnerable to damage. The curved shape of an arch has some influence on the seismic performance of its structure, and an arch cave with reasonable shape has better seismic performance.