汶川地震中板式楼梯的破坏分析及抗震措施

Analysis of Earthquake Damage and Research of Anti-seismic Measures on Plate Stairs in Wenchuan Earthquake

通过汶川地震震害调查,对板式楼梯的破坏形态进行了重点研究,分析了建筑楼梯的震害机理.研究表明:在罕遇地震下,板式楼梯应考虑楼板平面内偏心轴力和竖向地震作用的影响;板式楼梯梯段板1/4～3/4跨度范围内应加强受压区配筋,以抵抗偏心轴力及竖向往复荷载下横截面受压区混凝土产生的拉应力,并从设计角度提出了楼梯结构抗震设计的改进措施.

Through the Wenchuan earthquake damage survey which mainly focuses on the analysis of the form of the de-struction of plate stairs,damage mechanisms of the stairs in the earthquake are analyzed.The research indicates that,in big earthquakes,the influence of partiality axis force of in-plane floor and vertical seismic action should be considered in plate-stair design.Pressure range reinforcement should be strengthened for plate stair section board in 1/4～3/4 span in order to resist eccentric axial force and tensile stress of concrete in transverse compressed area under vertical reciprocating load.And then from the perspective of design,stair anti-seismic design improvement measures are put forward.