改善农宅砌体结构前、后纵墙侧移刚度差综合措施研究

Studying on comprehensive details for reducing front and back wall lateral stiffness difference of rural masonry buildings

针对农宅砌体结构前、后纵墙侧移刚度差别较大,门窗洞口导致前纵墙整体性差,过梁容易引起墙体局部破坏等特点,提出了3项改进措施:在前纵墙两边增设异形构造柱、以贯通过梁取代各个过梁、在窗口下墙体角部容易开裂的部位布置拉筋.以一典型西北农宅砌体结构为例,对比分析了4种构造措施下结构的地震反应.分析表明,增加本文提出的构造措施,能够减少前、后纵墙位移差,减小结构扭转效应;布置贯通过梁后,减少了过梁导致的墙体局部破坏;窗洞下拉筋有效的减小窗下墙体的开裂;新构造措施对结构承受的水平地震力影响不大.研究表明,提出的构造措施可以有效提高农宅砌体结构整体抗震性能.

This paper proposed three seismic details for reducing front and back wall lateral stiffness difference,improving front wall integrity which be weaken by door and window openings.The three seismic details are adding L shaped tie column at the two side of front wall,substituting single lintel with continuous lintel and embedded steel into front wall below the windows.The earthquake response is comparative analyzed for a typical North-West rural masonry building with different seismic details.The results show that the seismic details would reduce torsional seismic response,avoiding local damage near two sides of lintels and reducing and delaying the wall crack below the windows.The new seismic details have few influences on base horizontal earthquake force.In short,the new seismic details are very effective for improving seismic performance of rural masonry buildings.