【摘要】 为研究大跨度飞机库结构的地震反应与抗震设计要求,对7度抗震设防、Ⅳ类场地条件下的国内某机库,采用不同地震波,进行了多维地震输入下的动力反应时程分析,考虑地震波沿结构水平单向、双向、三向和竖向输入的不同情况,从结构侧移、柱内力、屋盖结构杆件内力等方面进行了分析.结果表明:在多维地震作用下,地震波沿结构坐标轴正向或反向输入导致结构扭转方向不对称;与单向地震作用相比,多维地震作用可使得柱的一些内力和位移值增加显著;水平和竖向地震分别对屋盖网架和大门桁架起控制作用;三向地震作用下屋盖杆件地震内力总体上显著大于水平或竖向地震单独作用下的地震内力,且地震内力系数较大的杆件数量所占比例大.并分析了屋盖各部位地震内力系数大的杆件的分布情况.据此,建议对这种设计条件的大跨飞机库结构进行三向地震输入的抗震验算.更多还原

【Abstract】 Time-history response analyses of a long-span hangar based on site-class IV are conducted under different multi-dimensional earthquake inputs for the seismic fortification intensity of 7 to study its seismic response and requirements for seismic design.The lateral displacements of the structure,internal forces of its supporting columns and the members of the roof in the cases of one-,two-and three-dimensional seismic inputs were compared,respectively.The results show that,the dynamic analyses of three-dimensional seismic motions,different directions of the inputs,i.e.,positive or negative along the axis,result in asymmetric global torsions of the structure.Some displacements and internal forces of the columns are increased significantly with multidimensional earthquake inputs,compared with the one-dimensional ones.Seismic inputs in horizontal and vertical directions have different effects on different parts of the roof structure,dominating member forces of the space truss and the truss at the gate,respectively.Member forces of the roof from three-dimensional inputs are,as a whole,significantly greater than those only from inputs in horizontal or vertical directions,and a large portion of members has large seismic coefficients of member force.The distribution of roof members with large values of seismic coefficients was also illustrated.Therefore,it is recommended that,for long-span hangars in such conditions,seismic verification is needed,in which the effects of three-dimensional earthquake should be taken into account.更多还原