Study On Impact Resistance Of Spring Lattice Debris Flow Dam

Debris flow is a common phenomenon of natural disasters in mountains of china. It has the characteristics of sudden explosion, rapid movement, short duration and causing destructive results. The research of debris flow in China began in the1950s. So far, prevention and control measures of debris flow mainly include three types: prevention, early warning forecast and governance measures in China. Block dam is the main engineering measures in the regulation project. Block dam will lose prevention function when partial or full the dam is damaged by debris flow, and it can’t prevent mudslides effectively any more, instead, it will increase the dangers of debris flow significantly. The impact of the debris flow includes debris flow slurry pressure and the impact force of big stones, and the big stones tend to make the block dam damaged or even broken. In order to effectively improve the impact resistance of the dam, this paper proposes a new spring lattice debris flow dam, and the shock resistance of the new structure is analyzed. The main work includes:(1) According to the principle of adjustment the structure stiffness to reduce the impact to the dam, a new spring lattice debris flow dam is proposed based on the new concept of the dam in the front dissipate energy and the dam in the back bearing. Spring lattice dam consists of three parts:steel frame in the front, spring in the middle and dam in the back. Stone contact the steel frame firstly, and then the spring is condensed as the steel frame occurred plastic deformation, thus a part of energy is absorbed and avoid damage of the dam in the back.(2) Finite element model is established to simulate dynamic response of the normal gravity debris flow dam and spring lattice dam. And they are under the impact of the big stones. The stress distribution, impact, reaction force, displacement and energy distribution of ordinary gravity dam and spring lattice dam are analyzed to verify the superior shock resistance of the spring lattice dam.(3) In order to comprehensively the dynamic response of ordinary gravity dam and spring lattice dam, this paper respectively discusses the biggest impact force on the condition of different quality, different impact speed, different impact height and different spring stiffness. The maximum reaction force and displacement of ordinary gravity dam and spring lattice dam are analyzed. Influence rule of various parameters on the dam are obtained.(4) Research on Shock resistance test of ordinary gravity dam and spring lattice dam has been carried out on the basis of finite element analysis through the design of oblique impact test load platform. The key displacement, acceleration and stress distribution of the dam is recorded, and the impact process and failure mode of the structure are recorded by a high speed camera. The shock resistance of ordinary dam and spring lattice dam are analyzed on the condition of different impact height and different quality.According the above study, the dynamic response characteristics of the spring lattice debris flow dam under impacting load is known, as well as the shock resistance of ordinary dam. The study offers references to the practical application of the spring lattice dam.