Experiments and Numerical Modeling of a Rockfall Protective Wire Rope Fence

Abstract

generally account for a significant proportion of the total cost of the fences. Therefore, to reduce the number of energy absorbers and achieve lower cost while maintaining performance, energy absorbers are installed only at the end posts in the new type of fence. The new type of rock fence is examined in full-scale experiments carried out using a falling reinforced-concrete (RC) block that rolls down a natural slope without a navigation system for the block. In preparation for these tests, laboratory pre-tests on such components as energy absorbers, posts, and wire ropes were conducted to confirm their load-carrying capacities and structural behaviors. Furthermore, an experimental control system is introduced to investigate the impact force during collision. Moreover, numerical simulation was performed employing finite element code, LS-DYNA, to clarify the impact behavior by comparing numerical results with those obtained in actual-scale tests. ABSTRACT: To protect existing structures in mountainous areas against rockfall, various protection methods have been developed. A new type of rockfall protection fence is constructed of posts, wire ropes, and wire netting. To verify the performance of this rock fence, both experiments and numerical analysis based on finite element code were conducted. Collision tests were performed, in which a reinforced-concrete block rolled down a natural slope and struck the rock fence at the end of the slope. The performance of energy absorbers, which are effective in preventing wire ropes from breaking, was investigated. To measure the acceleration of a reinforced-concrete block rolling down a steep slope, a new system of measuring instruments was developed.