Experiments and simulation of block motion in underwater bench blasting

Abstract

The blasting mechanism underlying drilling and blasting of underwater rocks, as an important component of the engineering blasting technology, has not been systematically studied. Laboratory model experiments are expensive and take a long time, while field tests fail to obtain timeous breakage and accumulation effects of underwater blasting, and may even be impossible. Considering this, a model experiment of underwater concrete bench blasting was designed, and the motion of blasted blocks was observed and evaluated with a high-speed camera. Then, numerical simulation was conducted based on Fluent and an engineering discrete element method coupling program complied using the application programming interface. Results show that the blocks form a bulge in the underwater blasting experiment under action of blast waves and expansion in the first period of bubble pulsation. Then, some blocks shrink in the first period of bubble pulsation. As the charge increases, the blast load exerts larger disturbance on the block group, resulting in significant motion of blasted blocks along the vertical direction. At the same time, the horizontal displacement of blasted blocks in the throwing direction increases.

Fluid–Solid Mixing Transfer Mechanism and Flow Patterns of the Double-Layered Impeller Stirring Tank by the CFD-DEM Method

“…where ρp, vp, and dp represent the density, velocity, and diameter. Cd and Rep denote the drag coefficient and Reynolds number [44][45][46], with their expressions as follows: During the chemical reaction course, the density of the liquid is lower than the density of the particles, and the virtual mass force and Basset force are deleted. Thus, the equation can be expressed as follows:…”

“…where ρ p , v p , and d p represent the density, velocity, and diameter. C d and Re p denote the drag coefficient and Reynolds number [44][45][46], with their expressions as follows:…”

Identification of the blasting vibration characteristics of groundwater-sealed tunnel

“…Blasting, which is an economical and effective means of excavation, is widely used in mining, railway, highway tunnel, hydropower engineering, groundwater-sealed tunnel, and demolition of urban high-rise buildings 1 – 3 . Groundwater-sealed tunnel storage refers to an underground space system that utilizes the principle of water sealing to store oil and gas energy, excavated in a certain depth of rock below a stable groundwater level.…”