Optimal array layout of cylindrical baffles to reduce energy of rock avalanche

The array of baffles protection structure is a flow resistance structure with good drainage, blocking, and intercepting effects on the rock avalanches. In this research, the physical model test on rock avalanches was conducted. Three parameters (column spacing, row spacing, and a number of baffles) were used as indicators to determine the optimal layout of the array of baffles for energy efficiency consumption blocking. Then, the lattice Boltzmann numerical simulation method was used to build a numerical simulation model of rock avalanches-array of the baffles-hazard-bearing body to obtain the rock's velocity attenuation and flow trajectory avalanches in the impact baffle protection structure. Finally, the results of the physical model test and the numerical simulation were mutually confirmed. The following conclusions were drawn through two methods of physical model test and numerical simulation. (1) The optimal layout parameters of array of baffles were determined as three rows of array of baffles (The number of baffles in each row is 7, 8, 9), column spacing Sc=3.5, and row spacing Sr=4.5. (2) Under the conditions of high baffle density (such as Sc=1.5, 2.5), the rock avalanches would produce a certain degree of circumfluence, which would increase the fluid velocity by at least 24.5% over the average velocity, so the column spacing density should be increased appropriately to achieve the optimal effect of reducing the energy of rock avalanches. (3) In the event of a prototype grooved rock avalanches with a velocity close to 24.5 m/s and a flow depth of about 1.5 m, the three-row array of baffles protection with the parameters Sc*=1.18 m and Sr* =1.51 m could be arranged, playing the role of optimizing the array of baffles to guide the flow and block the energy consumption. LBM experiments can be used to replace laboratory experiments to some extent. Further Lattice Boltzmann method-Discrete element method (LBM-DEM) studies are required before applications to practical engineering.