... learning (ML) models were employed. Specifically, k-nearest neighbors (KNN) and multi-layer perceptron (MLP) were used for both models. The aim of the regression ML models was to predict the depth of damage based on the maximum tangential stress around the opening and the crack initiation (CI) threshold...

... international journal geologist grout annulus propagation circumference geology reservoir characterization displacement axial displacement initiation masoumi confinement equation hagan wellbore design saydam geological subdiscipline grout interface rock mechanic dilation 15th ISRM Congress...

... geological subdiscipline strength mining science numerical validation international journal technology mpa pre-cracked specimen rock mechanic numerical simulation initiation literature strain 15th ISRM Congress 2023 & 72nd Geomechanics Colloquium. Schubert & Kluckner (eds.) © ÖGG Behaviour...

... produce the macroscopic response of the rocks. The role of inter-granular bond strength, initial microfractures present, and inter-granular bond stiffness were investigated. It was found that initial micro-fractures present in a rock sample is the main reason for producing the bi-modularity in rock...

... ABSTRACT: We address the controversy surrounding the use of the Brazilian test to estimate the tensile strength of rock-like materials. Due to its indirect nature, the tensile strength is inferred from the critical load by assuming that cracking initiates at the centre of the sample. We...

... Abstract In this paper, the role of micro-scale properties and behavior on the detection of crack initiation, propagation and geochemical alteration is examined through three topics: (1) identification of a geophysical precursor for a system transitioning from meta-stability to unstable...

... Abstract Rock fragmentation by blasting is the most efficient way of rock breakage in hard rock mining. The interaction of the stress waves are the parameters that control the damage around blastholes. Hence, the initiation timing of each blasthole is an important parameter. In this study...

... loading observation dic initiation sensitivity Abstract In order to study the effect of prefabricated elliptical holes on rock failure characteristics, static and dynamic compressive tests were conducted on rocks with elliptical holes of different geometries combined with digital image...

... Abstract We present detailed comparisons between theoretical predictions and experiments for the initiation of radial hydraulic fractures transverse to a wellbore. Most of these experiments provide a measure of the time evolution of pressure, length, opening and flux entering the fracture...

... Abstract This paper aims to simulate the spalling failure behavior in hard rock based on a self-developed numerical model, i.e. a rock discontinuous cellular automaton (RDCA). A crack initiation and propagation criterion is proposed based on the plastic strain, which is used to link...

... deep oil wells may change permeability (to 2–5%) which stipulates redistribution of seepages and the flow rate variation. Reservoir Characterization heterogeneity variation Earthquake Russian Academy vicinity focal parameter initiation evolution reservoir geomechanics Seismology...

... Engineering, Queensland, Australia M. Rinne Fracom Ltd, Kirkkonummi, Finland ABSTRACT: Fracture propagation code (FRACOD) is a two-dimensional Displacement Discontinuity Method (DDM) com- puter code that was designed to simulate fracture initiation and propagation. The latest development introduced...

... ABSTRACT Various crack types have been reported to initiate from a pre-existing flaw in rocks under compression. In addition to the most commonly observed tensile wing cracks, anti-wing cracks propagating in an opposite direction to that of the tensile wing cracks are also observed...

... was identified in quartz grains, but no preferential orientation was found in these cracks. It showed that the degradation in this stage was caused by the growth of pre existing cracks mainly in quartz grains. During the second stage, the crack initiation was more frequently than previous stage. Crack...

... ABSTRACT The mechanism of crack initiation and propagation is studied by using rock-like modeling material. Rectangular prismatic specimens with an oblique central crack (a pre-existing flaw) are used in the experimental study. The crack propagation process is observed in the specimens under...

... between two contiguous blocks at the initiation of slope failure. It also indicates that the limit equilibrium condition may not occur along the interfaces of rock blocks at the initiation of slope failure. The determination of realistic interaction forces around each block will be very important in rock...

... of rock, the stress threshold value of meso-damage of rock is given, and the stress-strain complete process curve of rock is divided into 5 segments. The initial rock damage propagation law is given in this paper. 1 INTRODUCTION The study of rock damage mechanics is, at present, one of the important...

... reservoir geomechanics criterion prediction Diederich Upstream Oil & Gas transition Coalescence crack propagation Reservoir Characterization extreme end initiation high gsi rockmass rockmass behaviour GSI strength rockmass threshold competency scale unified procedure hoek...

... Abstract A series of numerical tests of hydraulic fracturing in heterogeneous rocks were performed to investigate the influence of pore pressure magnitude and gradient on initiation and propagation of tensile fractures. The numerical tests were run with a Rock Failure Process Analysis code, F...

... Fracture initiation and propagation, being one of the most intensive subjects in rock mechanics; contribute significantly to the deformation of jointed rock masses. An experimental study on fractured granitic rock was carried out to determine the peak strength of specimen under triaxial loading...