关于建立拉/压弯剪扭统一计算公式的讨论

钢筋混凝土构件在拉/压弯剪扭的不同内力组合下,目前还没有一种可以被普遍接受的统一破坏理论。理论上长期不完善,直接影响到钢筋混凝土结构在各种复杂组合荷载下(特别是灾害荷载下)的强度计算。GB50010-2002《混凝土结构设计规范》1]用试验数据回归的方法给出压弯剪扭组合受力下的剪扭承载力计算公式,但缺少拉弯剪扭的承载力计算公式。目前的修订工作是在2002版基础上加以改进,力图增加拉弯剪扭组合情况的承载力计算。作者基于近期的研究认为,钢筋混凝土构件在拉/压弯剪扭共同作用下的统一的计算公式实际上并没有解决,尽管根据目前的认识水平,新规范中构件承载力计算主要还是依靠试验数据回归,但是其基本内涵应该尽可能准确地反映构件破坏的机理,表达形式应该简明。这一点应该引起规范修订足够的重视。本文将以建立钢筋混凝土普通矩形截面构件在拉/压弯剪扭组合受力状态下的承载力公式为例,说明这个问题,以供今后进一步修改规范时参考。

Discussion on building of carrying capacity of reinforced concrete members under combined load effects

Until now a practical unified theory for simply describing carrying capacity of reinforced concrete （ R. C. ） members under various combined loads has not been recognized by engineering community. It directly prevents from systematically understanding the behavior of R. C. structures under different combinations of external loads, especially under hazard loads. By regression analysis, China Design Code GB50010 - 2002 for concrete structures has proposed bearing capacity formulas of shear and torsion for R. C. elements subjected to bending, compression, but it does not includes tension. Based on GB50010 -2002, a most recent revision has made some improvements, and attempted to make up it. From authors＇ point of view, although the regression analysis is still used, a practical unified theory for simply describing carrying capacity of R. C. members should reflect the failure mechanisms as closely as possible and be expressed simply. As example, in the present paper, the authors will give some discussion on building a practical unified R.C. theory for prismatic members.