Research On The Performance Analysis Of Highway Slope Passive Flexible Protection Net

Passive flexible protective technology is a kind of light protective means, which isoften used in the regulation project in collapse rock falls. With its advantages of highprotective level, good protective effect, fast installation and low engineering cost it hasgot a lot of promotion and application in the highway industry. At present the researchfor passive protection system focuses on the collapse and fall (rolling stone), containingits trajectories, energy consumption characteristics, impact deformation behavior andpeak force, etc. While the research for the effect factors of the performance of flexibleprotective fence is less, which remains to be further studied to provide more referencesfor engineering design.This research mainly uses the finite element software ANSYS LS-DYNA to establishnumerical analysis model for calculating and studing the protection performance ofhighway slope passive flexible fence. First of all, through reviewing the data resource athome and abroad, the engineering application and protective performance of passiveflexible protective net was summarized. And the protection principle of flexibleprotection technology and technical index was introduced to provide theoretical basisfor subsequent modeling. Then, the finite element software was used to model RX-050passive flexible net. In the process of modeling, the effect of anchor bolt anddecompression was simplified. The local numerical analysis model of the net-ropesystem was created. By calculation and analysis the energy distribution of componentsconformed to the rule of energy and load transfer reduction step by step betweencomponents of the passive flexible protection systems. At the same time, the dynamicsituation of two numerical models with support rope8mm and16mm was comparedand analyzed. Finally, according to the different influence factors numerical modelunder different conditions was set up to analyze the changing rule of the net energy, netand rope deformation and axial force under various working conditions, thus obtainingthe relationship between different influence factors and the performance of the flexiblefence.The main research results of this paper are as follow:(1)When the rock fall protectionsystem is under the same stress condition, the increase of the support line sectional areacan enhance support and reinforcement function of the network, reduce the stress of thesupport line component.(2) The rock fall speed has the direct influence on the performance of flexible protective fence. The energy absorption efficiency, deformationcapacity and maximum of net and rope are increased with the increase of rock fall speedincreases.(3) Under the same energy, the smaller the radius of the rock fall, the morelikely it produces "bullet effect", making local damage conducted.(4) When the rockfall hit fence with sharp point section, the local damage of network is more likely tooccur. The impact area decrease is more likely to cause local stress concentration of thenet.(5) When the height of protection net is conformed, the increase of spacing isbeneficial to improve the shock resistance of passive protection system components.(6)Under the function of rockfall impact kinetic energy, the protection performance ofdiamond mesh fence decreased with the increase of mesh specifications.