This paper focuses on the fire risk assessment for commercial complex, as the variety of fire accidental triggers inside could be a big threat to the public fire safety, leading to catastrophic loss in human lives and properties. Both the qualitative and quantitative analysis were imposed on a typical large commercial complex to recognize the potential fire-causative factors in this paper. Applying the fault tree analysis, the basic events leading to fire are acquired, and they are then further reclassified based on the analytic hierarchy process. Taking the damage of the accident as the target layer and the fire-causative factors, the equipment operation factors and firefighting factors as the criterion layer, the assessment index is well established. The risk of each factor is quantitatively evaluated, and the effect of each factor on the target layer is analyzed. The result of the fault tree analysis and analytic hierarchy process shows good consistency, in which human behavior is the main factor leading to the fire occurrence, followed by the combustible material, the rescue speed and the staff assignment factors. The results are beneficial for general decisions and measures in public fire safety management.

The influence of blasting energy on blasting fragmentation and damage of reserved rock is important for safety and schedule of drill-blasting construction in coal mine. This study is aimed at investigating the dynamic mechanical properties of mudstone in coal mine using the energy characterization method, and their quantitative relation formula was also developed. The impact compression experiments of mudstone in Huainan mining area were conducted to study the saturated mudstone dynamic mechanism, crack properties, and energy dissipation law using the diameter 50 mm split Hopkinson pressure bar (SHPB). The results show that under the back-and-forth reflection of the stress wave, the saturated mudstone specimens are characterized by circumferential failure and axial splitting damage, which appear in the rock grain interface. By energy analysis, the energy dissipation per volume (EDV), energy dissipation per mass (EDM), and absorption impedance energy ratio (AIER) are used to represent the energy dissipation characteristic of mudstone. And the AIER is the best index. Additionally, there is the quadratic function relationship between three indexes and average strain ratio, showing the dependence of the strain ratio.

Spontaneous combustion of coal piles threatens the production and transportation safety of coal mining, which is attracting more and more attention. To understand the underlying physics, conducting pore-scale research on the spontaneous combustion of coal piles is critical. To enable pore-scale research, a pore-scale model of the spontaneous combustion of a coal pile is described, and governing equations are introduced. To understand the competition between airflow, heat–mass transfer, and oxidation reaction, the lattice Boltzmann method (LBM) is utilized, which offers distinct advantages in handling complex pore geometries, multi-physics coupling, and reactive transport at the pore scale. The present model integrates, for the first time in a pore-scale LB framework, airflow driven by thermal buoyancy, convective heat and mass transfer, and Arrhenius-type oxidation kinetics within a realistic coal pile geometry. After the numerical method is validated, the effects of inflowing air velocity, inflowing air temperature, oxygen concentration, and coal particle size are discussed. With an increase in inflowing air velocity, convective heat transfer is enhanced, and the coal pile maximum temperature decreases monotonically. According to the Arrhenius equation, with an increase in the inflowing air temperature and oxygen concentration, the oxidation reaction is accelerated, and the coal pile maximum temperature increases. When the size of the coal particle increases, the oxidation reactive area decreases, and the coal pile maximum temperature decreases, while the steady temperature is not affected.