Experimental and numerical impact models of protection fences

Abstract

The essential requirements for the protection of structures in mountainous areas against rockfalls have led to the development of various types of protection fences. Herein, we conducted impact tests on the protection fence by changing the heights of its posts and collision positions to evaluate adequately and precisely the absorbable capacity of the impact energy. In all experimental cases, the protection fence, which had a span of 5 m and posts with the heights of 2 and 3 m, exhibited an outstanding capacity for dissipating the impact energy of 50 kJ in accordance with a rational arrangement of energy absorbers, which caused the effective slipping of wire ropes. In addition, the simplest possible assumptions adopted in numerical simulations are presented clearly and in detail in terms of the choice of finite element shapes, constitutive laws, and contact conditions, so that the model of the numerical simulation can reproduce successfully the dynamic behavior of the protection fence. Furthermore, this numerical model can aid or replace the full-scale tests to attain an improved capacity for absorbing the energy of rockfall.