基于Hertz理论的泥石流大块石冲击力修正计算

发布时间：2018-11-05 13:42

【摘要】：为合理确定泥石流块石对构筑物的冲击力,以Hertz接触理论和结构力学为基础,建立泥石流大块石对桥梁的冲击模型,量化冲击系统中对象的材料特性、相对尺寸大小及结构变位对冲击力的影响,导出泥石流大块石冲击力修正计算公式.结果表明:材料修正系数在0.20~0.45之间,其值与材料屈服强度Y成正比,与冲击系统的等效模量E呈反相关关系;球径比修正系数随构筑物尺寸的增大先迅速增大而后平稳增长;结构变位修正系数受墩顶约束及冲击位置双重影响.将提出的计算方法应用于登基沟泥石流大块石对桥墩的冲击力计算,结果仅为Hertz弹性碰撞理论的6.7%,冲击力-冲击速度关系曲线平缓,与工程实践估值结果基本一致.
[Abstract]:In order to reasonably determine the impact force of debris flow block on structure, based on Hertz contact theory and structural mechanics, the impact model of debris flow massive stone on bridge is established, and the material characteristics of objects in impact system are quantified. The influence of the relative size and the structural displacement on the impact force is derived, and the modified formula for the impact force of large debris flow rock mass is derived. The results show that the correction coefficient of the material is between 0.20 and 0.45, which is directly proportional to the yield strength of the material, and is inversely correlated with the equivalent modulus E of the impact system. The spherical diameter ratio correction coefficient increases rapidly with the increase of the structure size and then increases steadily, and the structural displacement correction coefficient is affected by the pier top constraint and the impact position. The proposed method is applied to the calculation of the impact force of debris flows on the pier in Dengjigou. The result is only 6.7 of Hertz's elastic impact theory, and the curve of the relation between impact force and impact velocity is gentle, which is basically consistent with the result of engineering practice.
【作者单位】：山地灾害与地表过程重点实验室(中国科学院);中国科学院水利部成都山地灾害与环境研究所;中国科学院大学;
【基金】：国家自然科学基金重点项目(41030742)
【分类号】：P642.23

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