强震区高拱坝横缝配筋抗震措施

Reinforcements across contraction joints of high arch dams to resist strong earthquakes

为了增强拱坝在强地震作用下的整体性,可采取横缝配筋抗震措施,但这方面的研究还很不完善。该文基于钢筋与周围混凝土的粘结滑移特性,提出了考虑钢筋滑移的拱坝横缝配筋动力非线性分析模型,并加入到程序ADAP-88中。作为工程应用,对292m高的小湾拱坝的横缝配筋问题进行了详细研究,结果表明,在合理配筋时,横缝开度减小,拱向作用增强;钢筋不屈服,钢筋滑移不大;钢筋最大粘结长度约为25倍钢筋直径。因此,为了节约钢筋,拱坝横缝配筋可以考虑按插筋方案布置。

Reinforcements across contraction joints in arch dams are used to enhance the strength of arch dams during strong earthquakes, but little design data is available for the joint reinforcements. A numerical model considering the effects of the bond and slip behavior between steel bars and the surrounding concrete was incorporated into the computer program ADAP88 to evaluate the influence of reinforced contraction joints on the nonlinear seismic response of arch dams. The 292 m Xiaowan high arch dam was analyzed in detail. The results demonstrate that, for appropriate reinforcing conditions, the joint opening can be reduced by reinforcing the arch action to some extent. Furthermore, the stress in the steel bars can be controlled within the yield strength limit and the slip deformation of the steel bars is small. The maximum bond length of the reinforcements in the concrete is approximately 25 times the steel bar diameter. Thus, it is more economical and convenient to place steel dowels across the contraction joints instead of placing reinforcements through the whole arch length.