单向布置并张拉预应力筋双向板的设计方法

针对双向板难以实现双向布置并张拉预应力筋的问题,提出在双向板中单向布置并张拉预应力筋的设计思想.给出此类双向板的承载力及预应力效应计算、裂缝及变形验算等设计要点,并对单向布筋的四边简支双向板进行分析,探讨了预应力筋布置形式对其极限荷载、主次弯矩分布、裂缝及变形的影响.结果表明,预应力筋总量相同时,中间板带布筋越多,对结构越有利.

Design method for two-way slabs with one-way arrangement and tension of prestressing tendons

Considering the problem that prestressing tendons in two-way slabs can not be arranged and tensioned in two ways,a design idea that prestressing tendons in two-way slabs are arranged and tensioned in one way is presented.Some design points are given including the calculation of carrying capacity and prestress effects,and the checking computations of crack and deformation.The analysis is performed for a two-way slab simply supported at four sides with one-way arrangement of prestressing tendons.The influences of arrangement types of prestressing tendons to its ultimate loads,distribution of primary moment and secondary moment,crack and deformation are discussed.The results show that when the total number is constant,the more prestressing tendons are arranged in center strip,the better it is for slabs.