跨地裂缝带支撑RC框架结构振动台试验研究

研究跨地裂缝结构在地震作用下的灾害控制措施，以一个跨越西安f₄地裂缝的5层RC框架结构为研究对象，通过对非一致性地震激励下跨地裂缝无支撑结构和不同布置形式的带支撑结构进行数值分析对比，找出了跨地裂缝结构的薄弱位置，确定了合理的支撑布置方案，并以此为依据设计并完成了一个缩尺比为1:15的跨地裂缝带支撑结构振动台试验，分析了不同工况下跨地裂缝带支撑结构的抗震性能，得到了该结构在不同地震激励下的破坏形态、动力特性和动力响应规律。研究结果表明:地裂缝的存在增大了跨地裂缝结构的动力响应，且上盘对结构的影响大于下盘；该支撑布置提高了跨地裂缝结构的抗侧刚度，减小了结构在地裂缝和地震共同作用下的动力反应；同时，支撑在结构破坏前发生屈服，其屈服变形不仅耗散了地震能量，降低了结构损伤，而且实现了多道抗震设防，使跨地裂缝结构得到了有效保护。该研究成果为跨越地裂缝结构灾害控制提供了科学依据。

RESEARCH ON SHAKING TABLE TEST OF FRAME STRUCTURE CROSSING THE GROUND FISSURE WITH BRACES

To study the measures of disaster control for the structure crossing a ground fissure with steel braces,a 5 story RC frame crossing a ground fissure f4 was taken as an example.A finite element analysis was carried out on structures without steel braces and those with different arrangements of steel braces.The weak part of the structure crossing a ground fissure was found and the scheme of arrangement for the test was determined.The shaking table test on a 1:15 scaled model structure crossing a ground fissure with braces was designed and tested.The aseismic behavior of the structure was analyzed in different cases.The dynamic characteristics,dynamic responses and failure mechanism of the structure under different excitations were obtained from the test.The research shows that the ground fissure site enhanced the dynamic response of the structure under an earthquake,and the impact from the hanging-wall was greater than that from the footwall.The steel braces used in this scheme provided lateral stiffness for the structure,and they reduced the dynamic response of the structure under the combined action of a ground fissure and an earthquake.The braces yielded before the structural members was destroyed,which dissipated earthquake input energy through their deformation and reduced structural damage.This indicated that the brace of a structure has a multiple aseismic fortification function so that the structure crossing the ground fissure was protected effectively.The research results provide a scientific basis for the disaster control of structures crossing ground fissures.