In extra-thick coal seams, mining operations can lead to large-scale disturbances, complex overburden structures, and frequent and strong strata behavior in the stope, which are serious threats to mine safety. This study analyzed the overburden structure and strata behavior and proposed the technique of confined blasting in water-filled deep holes as a measure to prevent strong rock pressure. I...

Blasting demolition plays an important role in building demolition, and numerical-simulation methods can facilitate the optimization of blasting-demolition schemes. To study influence delay-time differences between columns on blasting effect small-aspect-ratio reinforced concrete structures, a separated common node model structures was established through finite element numerical simulation sof...

Blasting is one of the primary aspects mining operations, and its environmental effects interfere with safety lives property. Therefore, it essential to accurately estimate impact blasting, i.e., peak particle velocity (PPV). In this study, a regular random forest (RF) model was developed using 102 blasting samples that were collected from an open granite mine. The inputs included six parameter...

The research aims to investigate the failure characteristics of rock caused by blasting under high stress, explore energy generation and its transfer release in effects blasting. Physical experiments numerical simulations were performed. results showed that, as with AE time-series data, attenuation time activity increases number events, thereby decreasing overall stability samples. In terms spa...

This study investigated occupational exposure to silica dust of 48 workers in stone cutting, glass making, ceramic, and sand blasting plants in the north of Iran. Samples were collected from the breathing zone using a personal sampling pump and a size-selective cyclone. Sample filters and blanks were analysed using infrared spectroscopy. The mean sampling period was 4.83 h. Mean exposure of wor...

We developed a technique for constructing light diffusing devices comprised of a flexible shape memory polymer (SMP) cylindrical diffuser attached to the tip of an optical fiber. The devices are fabricated by casting an SMP rod over the cleaved tip of an optical fiber and media blasting the SMP rod to create a light diffusing surface. The axial and polar emission profiles and circumferential (a...

The existence of karst cavities has an important impact on the safety foundation pit excavation projects. It is engineering guiding value to study influence blasting process pits and how optimize stiffness cement mortar improve effect. Based bench project Shenzhen Dayun Foundation Pit Project, this paper adopts SPH-FEM coupling calculation method cavities, cavity-filling water silt clay rock-bl...

Powder blasting, or Abrasive Jet Machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials like glass, silicon and ceramics. By introducing electroplated copper as a new mask material, the feature size of this process was decreased. It was found that blas...

We present an encoding of pseudo-Boolean constraints based on decomposition with respect to a residual number system. We illustrate that careful selection of the base for the residual number system, and when bit-blasting modulo arithmetic, results in a powerful approach when solving hard pseudo-Boolean constraints. We demonstrate, using a range of pseudo-Boolean constraint solvers, that the obt...