Rock dynamics deals with the responses of rock (materials and masses) under dynamic stress fields, where an increased rate of loading (or impulsive loading) induces a change in the mechanical behaviour of the rock materials and rock masses (Zhou & Zhao 2011).
Dynamic loads include explosion, impact, and seismic, that are typically in the form of time histories of particle acceleration, velocity, or displacement. Distribution of dynamic stress field is in the form of propagating stress waves. Wave propagation in rock masses is governed by the wave transmission and transformation across the rock discontinuities in the rock masses, which forms a major topic of rock dynamics.
Response of rock materials and rock masses under dynamic stress are at different scales, including rock material fracturing and failure, sliding along the rock joints and rock block movements. Rock material fracturing, for example, is a dynamic micro-scale process leading to macro-scale deformation and failure. Rock fracturing is a dynamic process often associated with sudden energy release forming dynamic stress waves.
Rock dynamics has applications in civil, mining, energy and environmental engineering encountering dynamic loads and behaviours, e.g., rock excavation and fragmentation by blasting, tunnelling and slope stability and support under earthquakes, protection of rock falls, rock burst in deep mines, fracturing of hot rock in geothermal fields, hazard and risk control due to explosion and blast.
This keynote addresses advancements in some of the topics of rock dynamics and applications, specifically on numerical modelling methods, laboratory testing techniques and tunnel stability under explosive loading.
ABSTRACT: Iron ore mining was carried out in the Lorraine district in the north-east of France for several centuries. The predominant mining method was bord and pillar, with pillar extraction in some areas. The orebody consists of several layers and mining was done on multiple levels. There is no evidence today that a formal design method for pillar size was in use. Mining ceased in 1975. It is important to evaluate pillar stability and hence surface stability as the region has been extensively built up. It is an important input parameter in the surface stability risk analysis that is done for all historical mining areas in France by INERIS.
The method used to determine the optimal strength formula for coal pillars in South Africa has been used successfully for the iron ore pillars in the Lorraine basin in France. The method is based on obtaining the best possible distinction between cases of failed and stable pillars using the safety factor and arriving at a mean safety factor of 1.0 for the population of failed pillars.
Mehinrad, A. (Bakhtiary Joint Venture Consultants (BJVC)) | Binazadeh, Kh. (Bakhtiary Joint Venture Consultants (BJVC)) | Gheshmipour, A. (Bakhtiary Joint Venture Consultants (BJVC)) | Hamzehpour, H. (Bakhtiary Joint Venture Consultants (BJVC)) | Chehreh, H. (Bakhtiary Joint Venture Consultants (BJVC)) | Haftani, M. (Bakhtiary Joint Venture Consultants (BJVC))
da Fontoura, S.A.B. (Pontifical Catholic University of Rio de Janeiro) | Inoue, N. (Pontifical Catholic University of Rio de Janeiro) | Martinez, I.M.R. (Pontifical Catholic University of Rio de Janeiro) | Cogollo, C. (Pontifical Catholic University of Rio de Janeiro) | Curry, D.A. (Baker Hughes Incorporated)