基于Hertz弹性理论和Thornton弹塑性假设的滚石冲击力的修正计算

摘要

The impact force of rockfall obtained by Hertz elastic collision theory is far more than the actual situation,and then it can not be applied in engineering practice.A modified equation for the impact force of rollfall on structures was built based on Hertz contact theory and the Thornton elastoplasticity hypothesis.The modified equation shows material properties,relative size of constrcution and structural change.Finally the modified equation is applied to anchored slide-resistant pile in 1# landslide control project of Erlang Mountain.The result shows that the calculation results of the impact force of the rollfall show that the correction coefficient is between 0.06 ～ 0.11 in 1 # landslide control project of Erlang Mountain,and the calculated results are in good agreement with the actual estimation.With the increase of the impact velocity the correction coefficient decreases sharply in the early stage and decreases smoothly after.The impact force increases with the increase of the strength of the rock and the speed of the rollfall.%以Hertz弹性碰撞理论所取得的滚石冲击力远远超过实际情况,无法应用于工程实践中.因此,以Hertz接触力学和Thornton弹塑性假设为基础,考虑构造物材料特性、冲击物的相对尺寸、结构变位等因素,建立了滚石对构造物的冲击力修正方程,最终以二郎山1#滑坡防治工程中滚石对锚索抗滑桩的冲击为例进行对比分析.结果表明:二郎山1#滑坡治理工程中,滚石冲击力计算结果显示,修正系数介于0.06～0.11之间,计算结果与实际估计较为一致;修正系数随冲击速度的增加而先急剧后平稳降低;落石冲击力随构造物强度、滚石速度的增大而增大.