This study is aimed at investigating the excavation damage characteristics of surrounding rock in Jinping deeply buried marble tunnels, China. According to acoustic detection results tunnel cross-sections under condition boring machine (TBM) obtained on site, PFC microscopic parameters Types II/III were simulated and calibrated through PFC2D program. In doing so, deeply-buried sections diversio...

The recovery of top coal in the caving face directly impacts efficiency mining resources. geological conditions and parameters are well known to be significant influences on coal. This study focused 9-301 working face, which is located a thick seam with large dip angle. seam’s angle, direction, mode interval were analyzed using PFC2D simulation. Field trials also carried out. results numerical ...

Hydraulic fracturing of a roof can attenuate the strong mineral pressure and stress transfer by creating series parallel artificial fractures in it, different forms hydraulic have effects on attenuation effect coal rock system. In this regard, study investigated influence law pre-cracks mechanical properties rock–coal combined body through PFC2D numerical simulation, following conclusions were ...

When the tunnel and underground engineering construction encounters water-rich soft broken surrounding rock, it is very easy to occur serious disasters such as mud inrush, water inrush collapse, threatening safety of construction. Taking ultracataclasite stratum exposed by 4th branch Xianglushan Tunnel in Central Yunnan Water Diversion Project an example, this has strong compactness, weak perme...

In recent years, an international consortium of research organizations conducted investigations at the Chicxulub Crater in Yucatan, Mexico, to better understand crater’s formation mechanisms and effects produced by impact asteroid that is hypothesized have caused one major life extinctions on Earth. This study aims reproduce asteroid’s mechanics matching computer simulations obtained with use d...

In order to guarantee perpendicularity of rotary cast-in-place pile in Karst areas, filling, like sand, etc., is commonly used between the inner steel casing and outer sleeve; while sleeve pulled out or a vertical load applied on top pile, sand will move, contact, push against each other, which leads recrushing; therefore, shear characteristics secondary breakage are meaningful problem study wi...

Complex geological conditions often make the blasting effect difficult to control. In order explore influence of soft-hard rock strata on characteristics, based PFC2D software, combined with particle expansion loading algorithm, numerical simulation experiments are carried out. Firstly, rationality method is verified by single-hole sandstone experiment. Then, composite established, and strata, ...

An underground coal gasification (UCG) process is strongly exothermic, which will cause thermal damage on rock cap. We proposed a new numerical model based two dimension particle flow code (PFC2D) to analyze the inception and extension of cracks pre-cracked red sandstone, were thermally treated at temperature 25~1000 °C. The results indicated that: (1) value DT obtained by extracting crack area...

Most geothermal energy is found in hot and dry rock (HDR), the total resources distributed at depths of 3-10 km are 20.9×10 6 EJ. HDR projects developed granite formations understanding control consumption percussive drilling essential. Thus, impact dissipated various processes including fracture granite, kinetic particles, heat. This study presents a numerical-experimental method to evaluate p...

Abstract Hydraulic fracturing and permeability enhancement are effective methods to improve low-permeability coal seams. However, few studies focused on increase permeability, there no suitable prediction for engineering applications. In this work, PFC2D software was used simulate seam hydraulic fracturing. The results were in a coupled mathematical model of the interaction between deformation ...