Study On The Seismic Design Method Of The Staggered Truss Framing Systerms

In recent years staggered truss steel framing has seen a nationwide renaissance.Staggered trusses provide excellent lateral bracing, light weight, rapid construction, lowcost and green environmental protection. For mid-rise buildings, there is little materialincrease in staggered trusses for resisting lateral loads because the trusses are veryefficient as part of lateral load resisting systems. The bearing capacity of sudden changewhich caused by the yielding of web members provide a poor ductility. Reference inthis paper, based on the above reasons, foreign related specification, gives the system aductility design method and using ETABS to evaluate the seismic resistance of themodel, which designed by the method.At first, the internal forces under the action of gravity load and horizontal load iscalculated according to the transfer system of staggered truss framing systems anddesign the chord members by bearing capacity. Based on the force when the chord formplastic hinge, calculate the force of the web members and columns. Consider theunderlying weakness when design the section, and give the corresponding internal forceamplification coefficient.The paper carried out response spectrum analysis, time history analysis and thestatic nonlinear analysis on the model. Analysis results are conform to the requirementsof the seismic design code in China. Can be seen from the pushover structuredeformation on the drawing, plastic hinge from the bottom up, all appeared in themiddle span of chord, in addition to the column foot, all the rest of the web member andcolumn in the elastic state. Ductility is very good.