通过对2-5跨非张拉预应力连续组合梁各受力阶段的分析,研究了配重大小、配重施加的合理范围以及负弯矩区后浇混凝土长度等非张拉预应力技术中一些关键参数的设计计算方法,并初步探讨了卸除配重后,在使用阶段非张拉预应力连续组合梁负弯矩区裂缝宽度及梁跨中变形的计算方法,提出因实施非张拉预应力技术而引起的反向挠度,可通过将卸除配重的反向荷载转化为满跨均布＂等效＂荷载,然后计算该＂等效＂荷载作用下的挠度而得到.结果表明,采用这种＂等效＂荷载方法计算得到的挠度最大相对误差不超过15%,能满足实际工程的精度要求.

By analyzing the loading stages of the continuous steel-concrete composite beams with 2-5 spans,some key parameters of the non-tension prestressing technology of the composite beams,such as the counterweights and their arrangement,as well as the post-cast length of concrete in the negative-moment region,are investigated.Then,the calculation methods of crack width in the negative-moment region and mid-span deformation of the composite beams are discussed after the removal of the counterweights.It is suggested that the reverse deflection induced by the non-tension prestressing can be obtained through two steps,namely,converting the reverse loads resulting from weight removing to the full-span uniform ＂equivalent＂ ones,and then calculating the deflections under the ＂equivalent＂ loads.With this two-step method,the requirements of practical engineering are satisfied well,and the maximum relative error of deflection keeps within 15%.