Research On Impact Performance Of Reinforced Flexible Protection Net Of Debris Flow

In recent years, the debris flows have occurred frequently in Gan Su province that have brought about serious harm to the local people’s life and property safety. The large debris flow of Zhouqu which occurred on August 8 shows that the main reason of prevention structure damage is the large rock in the debris flows. Therefore, it is of great significance to study the impact resistance of the prevention structure under the impact of large rock in the debris flow. In many prevention structures, flexible protection system of debris flow is a kind of very effective debris flow prevention measures, which has the advantages of low cost, simple construction, easy to maintenance, strong adaptability and does not constitute damage to the environment and landscape. It has been widely used in the prevention engineering in foreign countries. However, the academic research is not deep enough, especially in the study of debris flow large stone resistance to impact prevention basically in the blank stage.This paper takes the “the theory and experimental study of new latticed spatial prevention structures under the impact of debris flow” as the background, from the perspective of structure and mechanical, using explicit dynamic nonlinear software ANSYS/LS-DYNA numerical simulation to research the dynamic response characteristics when the flexible protection system of debris flow under impact force and protection system failure modes. The main research contents include the following aspects:(1)Analysis of the dynamic response characteristics of debris flow flexible protection system when the impact on the different parts. And contrasts analyzes the protection system of energy conversion, deformation and component of the axial force variation, and to evaluate the anti-shock performance of the protective system.Changing impact velocity, comparative analysis of effect of impact velocity on the shock resistance of debris flow flexible protection system, and the failure mode of protection system is obtained. The results shows that the support cable is a strong energy dissipation component in the protection system. The dynamic response of the impact site, the support cable constraint end and the connecting point is larger, should be strengthened in engineering design.(2)Put forward the reinforced debris flow flexible protective system with verticalslings, a more reasonable structure. By means of numerical simulation, the dynamic response of the strengthened type protection system and the common type protection system are compared and analyzed, and the impact resistance performance of the strengthened protection system is evaluated. Changing impact velocity, comparative analysis of the impact resistance performance of the strengthened protection system,and the failure mode of the strengthened protection system is obtained. The results shows that the vertical hanger indirectly protect the ring network is not destroyed, and the impact resistance of the protective system significantly enhanced.(3)Multi-stone randomly distributed and at the same time impact on the enhancing flexible protection system of debris flow, the energy and deformation of the protection system and the dynamic response characteristics are analyzed, and to assess their impact resistance.The research results of this paper provides some technical references for the engineering design of debris flow flexible protection system, which will lay a foundation for the future engineering application.