Abstract: Based on analysis of anti-cracking performance on RC structure by material mechanics, contrastive study of the calculation formula and data of the plastic influence coefficient of concrete under bending moment??was conducted. Taking the impact of section height during cracking on plastic parament??into conside ration, the calculation formula about cracking load of RC circular bridge pier pressure-bending model under lateral load was obtained based on balance principle of force and moment on circular section. Dynamic crack resistance model of piers and cracking load calcu lation were gained based on dynamic constitutive relationship of materials under impact load. The abovem ethod and calculation formula were verified by test of RC circular bridge pier model under lateral load and the impact of axial load on crack resistance property of RC circular section was discussed.

Key words: circular section, anti-cracking performance, plastic parament, plastic influence coefficient, collision

摘要： 在分析钢筋混凝土构件抗裂性能材料力学原理的基础上,对比研究了截面抵抗矩塑性影响系数的计算方 法和取值;考虑混凝土截面开裂时截面高度对其塑化系数影响,根据圆形截面上力和力矩的平衡原理,推导了圆 形钢筋混凝土桥墩在横向静载作用下的压弯模型开裂荷载计算公式;基于撞击荷载作用下材料动态本构关系,提 出桥墩动态抗裂性能分析模型与开裂荷载计算方法;通过钢筋混凝土圆形桥墩模型的侧向静载及撞击试验对该方 法和计算公式进行了验证,并讨论了轴向力对钢筋混凝土圆形截面抗裂性能的影响。

关键词: 圆形截面, 抗裂性能, 塑化系数, 塑性影响系数, 撞击