梁贯通式中心支撑钢框架地震剪力研究

Inter-story earthquake shear force for steel concentrically braced frames with continuous beam

为了保证梁贯通式中心支撑钢框架结构在大震下钢框架仍能正常工作,需要钢框架能够承担一定的水平地震力,而大震下底层框架柱所承担的地震剪力与小震下总剪力的比值取决于n和Δ_2/Δ_1,其中n为层柱刚度与层支撑刚度之比,Δ_2和Δ_1分别为大震和小震时的底层相对位移,因此本文对Δ_2/Δ_1的大小进行了研究,分别对单层、3层和6层的平面结构进行了动力弹塑性时程分析,最后给出建议的钢框架需要承担的地震剪力公式。

For steel concentrically braced frames with continuous beam,steel frames should be able to withstand certain earthquake shear force to make sure they still work under large earthquake. The ratio of the seismic shear force borne by the bottom frame columns under large earthquake and the total shear force under minor earthquake is determined by n,which is the ratio of column stiffness to bracing stiffness,and Δ2/Δ1,which is the ratio of the relative displacement of bottom frames under large and minor earthquakes. Therefore,the value of Δ2/Δ1 is studied in this paper. The dynamic elastoplastic time analysis is carried out for the plane structure of single,three and six layers respectively. Finally,the formula of seismic shear force for steel frames is proposed.