The coupled disaster of coal spontaneous combustion and gas explosion in the goaf threatens mine safety production. In order to further study mechanism disasters provide theoretical basis for prevention control, multi-field evolutions key influencing factors within methane condition had been investigated based on special designed hot experimental platform numerical simulations. Results show that leakages ventilation air into is positively related intensity combustion, but negatively ranges...

Abstract This work aims to examine the stress redistribution with evolving seismicity rates using a passive seismic tomographic tool. We compiled total of 26,000 events from two underground mines and partitioned them into multiple clusters in temporal sequence, each which contains 1000 events. To image associated rates, we then run studies cluster yield tomograms computed corresponding rate. found that high velocity anomalies grew increase they switched shrinking tendency under low rates....

In this work, quick hardening and high early strength engineered cementitious composites (ECC) was developed by using calcium sulfoaluminate (CSA) cement as the matrix material. The optimal mix design of CSA-ECC studied with emphasis on properties fluidity mechanical properties. It found that CSA incorporated 2% polycarboxylate-based superplasticizer (PSP), 1 % ultra-high-molecular weight polyethylene (UHMWPE) fiber to sand ratio 0.5 shown best performance in terms fluidity, flexural...

The influence of carbon and iron additives on the high-temperature decomposition behavior phosphogypsum (PG) is systematically investigated using XRD, SEM EDS.In absence carbon, a small amount anhydrite phase decomposed after sintering at 1200 °C for 2 h.However, undesirable oldhamite observed in RG/carbon50, PG/carbon/FeSO4 mixtures, PG/FeS2 mixtures embedded 800 h, respectively, which implies strong reducing atmosphere can promote to generate.In case PG/carbon 100 mixture, diffraction...

The storage of agricultural machinery (AM) poses a critical operational challenge that requires attention to attain China's "Carbon Peaking and Carbon Neutrality" objectives, due the carbon emissions fuel consumption associated with AM operations. Nevertheless, this matter has not garnered adequate consideration. Existing studies have rarely focused on optimizing parking locations for mitigate advance sustainability. This study employs TOPSIS-MCGP method explore sustainable location...

Using creep experiment to characterize the mechanical property of PMMA has been studied in this paper. Polynomial and first order exponential decay function have used fit data get curve PMMA. With finite element analysis method based on viscoelastic material models, simulation hot embossing process is carried out. Time influence emphasized. The result proved by experiments. It shown that model represents more compliance with experiments, can describe polymer deformation during embossing.

Fluid mud plays an important role in navigability ports and waterways. Characterizing monitoring the seismic properties of fluid can help understand its geotechnical behavior. Estimation wave velocities with high accuracy repeatability enables investigating behavior parameters like yield stress a nonintrusive reliable way. We perform ultrasonic reflection measurements laboratory to investigate propagation water/fluid-mud layered system. The component water layer inevitably brings kinematic...

Abstract Perturbations arising from mining operations significantly affect the stability of rock masses, and influences aggerates with rapid increase mining-operation depths during recent years. The subsurface structures major discontinuities subject to seismic hazards resulted shear-slip behaviors masses. In order identify regime calculate moment energy involved behaviors, we use discrete element modeling study shear slip failure along in an underground mine. recorded characteristic...

External sulfate attack is one of the situations that may cause gradual but severe damage in cementitious materials, which lead to cracking, increased permeability and strength loss.In this paper, thin-walled hollow cement paste cylinders with a wall thickness 2.5mm were made considering slow penetration process ions under continuous immersion condition.Three types longitudinal restraints applied on by means spring steel bars through specimens order facilitate non-, low-and high-restraint...

This paper analyzes the mechanism of buckling failure(slipping-bending) bedding slope. It uses physical model, numerical simulation and theoretical analysis. presents forming geological mechanical conditions, critical failure state discrimination early identification marks failure. finds that rock stratum dip angle greater than 20is a very important conditions for formation slipping-bending. The curved uplift in leading edge slope is an sign before slope, single layer thickness, length depth...

A continuous miner is one of wall mechanized coal face; its design quality and performance have directly effect on productivity economic benefits. pick a miner, contacting with rock, tool cutting force condition during it cuts determines loads the mechanism, wear tear, fabric vibration machine, basis for miner. By considering variety factors, mathematical model, including rock properties, structural parameters pick, sequence, established in paper, visualization software which can be...

AbstractUnderstanding stress redistribution within rock helps improve the safety and efficiency of mining projects. In order to better understand failure mechanism, a granite sample is prepared in manner that facilitates shear along preconceived cracks. The testing process this method employed several steps. First, loaded then monitored study field associated with failure. Passive acoustic emissions systems are used monitor seismic events during loading process. data obtained from test...