落石冲击旁山填方路基边坡破坏数值模拟

落石灾害造成山区中低等级公路路基滑塌灾害十分普遍,造成交通堵塞及大量的经济损失,甚至人员伤亡。以旁山沥青路面填方路基边坡为原型,采用显式动力学程序LSDYNA,研究了不同下落高度及入射角度的落石冲击作用下路基边坡的力学响应,揭示了落石冲击力和路基边坡的变形、能量转化与落石高度和入射角度的相关性。落石冲击力与入射角负相关,入射角为45°时路基变形最大。路肩位移、路基路面变形与下落高度正相关。路面结构对路基的保护作用与下落高度呈正相关。落石高度的变化主要影响路基路面变形,入射角的变化主要改变土体力学响应范围。研究成果可为路基边坡的落石灾害防护设计提供参考。

Numerical Modeling of Failure of Fill Roadbed Slope Beside Hillslope Induced by Rock-fall Impact

The failure of medium-low level roads induced by rock-fall is a familiar geohazard in mountainous area,which causes traffic jams and large economic loss,even loss of life.By taking the fill roadbed slope of asphalt road against the mountain as a prototype,this paper studies the mechanic response of the roadbed slope in rock-fall under the condition of various falling height and impact angle by using finite element software LS-DYNA.The correlations of falling height and impact angle with the rock-fall impact force,roadbed slope deformation and energy conversion are analyzed.Based on the modeling,it is found that the impact force is positive correlation with the impact angle and the deformation of the roadbed slope peaks when the impact angle equals 45°.The displacements of road shoulder and deformations of road surface are also positive correlation with falling height.The protection of pavement structure to the roadbed is positively associated with the falling height.The deformation of road surface depends mainly on the falling height of rock block,while the mechanic response of soil is predominantly controlled by impact angel.The study can provide some references for the design of roadbed slope protected from rock-fall.