为了探究施加预应力对带横缝拱坝抗震性能的影响,进行了振动台模型试验.试验模型采用新疆石门子拱坝的三心圆体型及特定刚性地基的方案(用型钢支架实现),研究了带横缝拱坝在动荷载作用下的反应规律.试验和计算结果表明,在施加预应力之后,不仅在一定程度上减小了横缝在强震荷载下的张开度,也在一定程度上提高了非整体拱坝结构的自振频率.与试验结果对比表明,计算预应力拱坝的简化数值模型基本上可以反映出拱坝在动力荷载作用下预应力钢丝或钢索对坝体动力反应的约束作用.
To explore the effect of prestressing forces on the seismic behaviors of arch dams,a set of model tests on shaking table were carried out.The arch dam model was made with a configuration of three-centered circular,which simulated Shi Men Zi arch dam built in Sinkiang.With a shape steel bracket,which simulated rigid foundations,the prestressed model was tested to study the dynamic behaviors of arch dams with contraction joints.The test and calculation results show that with prestressing not only the opening of the contraction joints is distinctly reduced,but also the natural frequency of arch dam increases in some degree.Comparison of the tested and numerical results shows a good agreement and it suggests that the simple numerical model proposed in this paper is reasonable for the arch dams with prestressed cables/wires under dynamic loadings.