Numerical analysis on energy-absorption of expanded polystyrene foam in radical uncoupled blast

Based on the large-scale finite element code LS-DYNA with explicit integration, the numerical simulations on radical uncoupled blast filled with expanded polystyrene (EPS) foam of three initial densities (12.0, 21.0, 27.0 kg·m-3 ) were performed. The distribution and evolution laws of concrete damage, hydrostatic pressure, velocity and acceleration of particles around the blasthole were analyzed. In addition, the comparisons between the radical foam uncoupled blast with the radical air and water uncoupled cases were also made. The result shows that EPS foam absorbs blast energy effectively, as well as reducing damaged zone around the blasthole. Then, the initial density of EPS foam ρ0 has a relatively great impact on the concrete's damage distribution. With the increase of ρ0, EPS foam has less capacity of energy absorption and vibration attenuation. By the adjustment of the decoupling coefficient Kd and ρ0 can achieve similar blast result. Finally, in order to achieve better result with a lower blast cost, the value of Kd is proposed to be less than 2.0 when using EPS foam as filling material. The conclusions obtained offer good reference for engineering blast practice.