The initiation, expansion, and penetration of microscopic cracks in rock is the macroscopic manifestation creep. This paper investigates mechanical creep characteristics fracture evolution processes masses with different angles, lengths, bridge dip angles. Single fractures, dual parallel groups are considered. approach comprises discrete element simulation based on continuum mechanics, utilizin...

Based on the proposed calculation method for determining different dip angle fracture permeability coefficients derived from well flow vibration equation and self-developed slug test system, research in a field fractured rock mass was carried out based underground water sealed cavern project of National Huangdao Petroleum Reserve. The formation lithology site granite gneiss, fractures were not ...

Response characteristics of key strata during the periodic weighting process in Dongjiahe coal mine were investigated using micro-seismic (MS) monitoring. Fracture types identified through moment tensor inversion. Finally, fracture mechanism roof was revealed from a microscopic viewpoint. The results show that there are three concentrations MS events distributed along dip direction. And two eve...

High-efficiency rock breaking by hydraulic jetting is the key to radial horizontal drilling technology. In order improve efficiency of jet in wells, based on LS-Dyna display dynamics, a numerical simulation model single-nozzle was established analyze influence different nozzle parameters rock-breaking effect. Then, spin multi-nozzle bit established, and rotation speeds effect analyzed. Finally,...

Objectives Mandibular third molar extraction is among the most commonly performed dental procedures. Fracture of the angle of mandible after third molar extraction is a rare complication of this procedure. Case Herein, we report fracture of the right angle of mandible immediately after extraction of mandibular right third molar in a 38-year old healthy female patient, which was surgically mana...

The area covered by this study is the county of Kakobola and its surroundings. Previous studies show that those related to depths gravity method, using other techniques, are not always carried out until now. main goal article gravimetric characterization our approach. interest only map lineaments know their dip, but also estimate these different anomalies. methods used for first total horizonta...

Faults are the most critical tectonic factors in geological structures, which have major economic impacts on mining economics. Thus it is necessary to understand faults in order to identify the actual risks and complications associated with mining. In the preliminary investigation of the Sonda-Jherruck coalfield, 3D geological modeling was not performed. The purpose of this work was to perform ...

Abstract Anisotropies exist in many sedimentary rocks, particularly naturally fractured reservoirs, causing horizontal stress anisotropies. Case studies indicate that when a rock formation contains high dip-angle fractures or factures (e.g. bedding planes), it has very distinguished stresses. In these cases, the conventional isotropic method for estimating stresses may give erroneous results. U...

background: the principal aim of this study was therefore to investigate association between family history of osteo porotic hip fracture, bmd and femur geometry in bushehr city in south of iran. methods: in this cross-sectional study, data were obtained from iranian multi-center osteoporosis study (imos) in bushehr. healthy men and women aged 50 to 75 years were selected based on randomized cl...