The Mechanism Of Deformation And Failure Of Debris Flow Dam Under The Shock Load

Debris flow is a common natural disaster in mountainous areas, it will have a huge impact in the process of movement. At the same time, the debris flow dam is one of the important engineering measures of comprehensive prevention and control system of debris flow disasters, and the debris flow dam sometimes will have damage failure under impact load. And once the dam damaged, the solid will participate in the debris flow movement, increased the impact force and enhance its destructive. So in order to reduce the damage of debris flow dam under the impact load of debris flow and security people's property and life safety maximumly, analysising the mechanism of deformation and failure of debris flow dam under shock load has important theoretical significance and practical value.This paper introduces the technical characteristics of debris flow dam structure and the calculation methods of impact force of debris flow at first, then on this basis, this paper analysises the damage process and damage mechanism of debris flow dam under shock load by dint of the field survey damage results of dam and aimulation softwares of LS-DYNA and ANSYS. The results obtained in this paper are as follows :(1)This paper analyzes the cha racteristics of impact force of debris flow based on the explaining of conditions and motion features of the debris flow,and according to the modified Hertz contact theory,it tries to deduce thequantization formula of dam when it has a elastic plastic deformation under the impact force of stone :(2)It analyses the damage features of the dam according to three types of damage of dam(damage of dam structrue, damage of dam foundation and damage of dam abutment) under the shock load. On the basis of this, the paper tries to put forward the failure mode of the dam foundation and the dam abutment under the impact load. After the dam foundation failure, the evolution mode of the dam collapse is as follows: dam foundation suffers erosion—dam foundation exposes outside—dam foundation suffers suspending—dam collapses. Damage evolution mode of dam abutment: rock and soil around the dam abutment suffer soaking and washing—structural stability of dam abutment brings down—dam abutment suffers erosion—dam abutment has a destroy.(3) The numerical simulation software s of LS-DYN A and ANSYS simulation are used to simulate the effect of debris flow in stones and debris flow slurry of impact force on the dam. According to the software of LS-DYNA simulation results, the paper analyzes the stone impact characteristics, and based on this, the paper inverse failure process of dam under stone impact force,at last,the paper analyzes the damage mechanism of rataining dam under stone impact force. According to the software of ANSYS simulation results, the paper analyzes the structure response under debris flow slurry impact force in three different dams. And it can be found that the slope ratio of dam more larger, the effect of debris flow slurry impact load on dam are more significant.