... ABSTRACT Axial-torsional coupled percussive drilling (ATCPD) is a practical technique for creating volumetric breaking patterns and increasing rate of penetration (ROP) of hard rocks. Our paper focus on numerical investigations on ATCPD process. We employed a continuous-discrete coupling...

... ABSTRACT The application of conicl PDC teeth to vibratory percussion drilling technology is expected to break deep hard rock efficiently and improve drilling efficiency. In this paper, the characteristics of conicl diamond tooth cutting and hard rock under percussion are investigated. Firstly...

... Study on temperature-time effect characteristics of hard rock under long-term load Longyun Zhang1, Geotechnical & Structural Engineering Research Center, Jinan, Shandong, China Shangyang Yang2* Department of Physics and Mathematics 2, Jinan, Shandong, China Copyright 2019 ARMA, American Rock Mechanics...

... ABSTRACT: The development of a constitutive model for hard rock goes hand in hand with conventional experiments, which provide information about the intrinsic failure properties of the material. To date most models are calibrated and validated using the macro stress-strain responses from...

...1. INTRODUCTION Unlike metals, rocks are brittle and fracture without significant plastic deformation prior to failure. Rocks have also a large ratio of compressive to tensile strength, known colloquially as a high brittleness index. This makes hard rocks, extraordinarily weaker under tensile...

... ABSTRACT: Post-peak mechanical properties of rock have important significance to reveal the mechanism of rock deformation, damage and fracture. Based on the conventional triaxial compression test of hard rock of the Tieshan mine, including marble, homogenic migmatite, banded migmatite, gneiss...

... of a roller disc (low wear rate) with the effectiveness of a drag tool (low cutting forces). Even though various realizations of the undercutting concept and actuated cutters exist in equipments designed to mechanically excavate hard rocks, the rock failure mechanism and its influencing factors are still...

...1. INTRODUCTION Currently, most of the soft ground tunnels and a significant portion of the mountainous tunnels are constructed using tunnel boring machines (TBMs) worldwide. TBMs are generally classified as hard rock and soft ground ones. The soft ground TBMs are also called as shield machines...

... input parameter hard rock brazilian tensile test peak stress tensile strength strength clumped particle model minimum ball size clump size structural geology reservoir characterization clump radius clump configuration simulation result tensile stress configuration brazilian...

.... The Particle Flow Code (PFC), a simulation code based on the distinct element method (DEM), is an effective numerical tool for simulating the failure process of hard rock [1]. By introducing the contact- and parallel-bond and clumped particle model [2], the code has become better able to express the brittle...

... Reservoir Characterization hard rock particle notional surface flat-jointed material strength normal stress resist relative rotation flat-jointed bpm bond state Microstructure structural geology Peak Load Potyondy flat-joint contact flat-jointed bonded-particle material Upstream...

... waste management Fluid Dynamics cavern flow in porous media hard rock Upstream Oil & Gas displacement Reservoir Characterization Rock Structure discontinuous rock mass Disposal discontinuity excavation Groundwater Flow Redistribution permeability change mechanics...

... failure, deformation and associated radial dilation near the tunnel boundary are highly dependent on confinement. Under low confinement condition, spalling is the dominant failure mode around underground excavations in brittle hard rocks subjected to high stresses. Once the crack damage stress level...

... beneath located hard rock mine workings, since: (i) due to stress relaxation, generally considered as a positive phenomenon, this layer is able to relieve stress concentrations within its own and the adjacent rock volume, however, due to the associated load transfer process the layer may develop...

... ABSTRACT : To verify the feasibility and efficiency of rotary-percussive drilling assisted by waterjets in very hard rocks, experiments on the performance of Polycrystalline Diamond Compact (PDC) cutters resisting different combined loads of static thrust, impact, cutting and waterjets...

... ABSTRACT : The objective of this work is to propose a constitutive model in order to describe coupled plastic damage behaviour of partially saturated concrete and hard rocks. Plastic behaviour is characterised by using two yield surfaces respectively for stress controlled and suction...

... 1974, Cundall et al. 1994). More recently, researchas shown that deep stopes in hard rock undergo significant time-dependent deformation (Malan 1998). The improved understanding of the time-dependent rock response provides a firm foundation for the assessment of different mining rates or multiple shift...

.... Reservoir Characterization Engineering mechanism Upstream Oil & Gas selection metals & mining geomechanics research centre Ground Control Toronto research chair new initiative reservoir geomechanics hard rock mechanics research rock mass laurentian university canadian rock mechanics...

... improvement, is an accurate model of hard rock cutting. Research undertaken at the Centre Mines Infrastructure (CMI) of the Ecole Nationale Supérieure des Mines de Paris (ENSMP) has shown that the compressive failure of brittle rock under the action of a pick is a combination of two fundamental modes: shear...

..., dozers, and crushers. The primary function of this equipment is rock handling. Up to now, few alternatives were offered to the mine owners or contractors for excavating hard rock. Having identified the need for a mobile rock excavating tool, Caterpillar has introduced the D9L Impact Ripper. This new...