Rock mechanical modelling of the Bentonite Rock Interaction Experiment, Äspö Hard Rock Laboratory, Sweden

Frutexites-like structures formed by iron oxidizing biofilms in the continental subsurface (Äspö Hard Rock Laboratory, Sweden)

Stromatolitic iron-rich structures have been reported from many ancient environments and are often described as Frutexites, a cryptic microfossil. Although microbial formation of such structures is likely, a clear relation to a microbial precursor is lacking so far. Here we report recent iron oxidizing biofilms which resemble the ancient Frutexites structures. The living Frutexites-like biofilm...

Pillar Design in the Hard Rock Mines of South Africa

This paper gives an overview of the difficulties associated with the design of hard rock pillars in South African mines. Recent examples of large scale pillar collapses in South Africa suggest that these were caused by weak partings which traversed the pillars. Currently two different methods are used to determine the strength of pillars, namely, empirical equations derived from back analyses o...

A New Concept for Selective Mechanical Mining of Hard Rock

Over the last several decades mechanical mining machines have developed into highly productive, light weight, mobile machines which are able to economically mine many soft rock ore bodies. Due to the utilization of disc cutters Tunnel Boring Machines, with great mass and limited mobility, have developed the ability to cut the hardest rocks at high production rates. Technological advancements ha...

Rock Mass Response to Coupled Mechanical Thermal Loading Äspö Pillar Stability Experiment, Sweden

Laboratory and Numerical Modelling of a Jointed Rock Mass

Laboratory tests were performed on 54 large size specimens of jointed rock mass under uniaxial loading conditions. Based on this experimental study, a methodology has been suggested to estimate strength and tangent modulus of rock masses through a weakness coefficient. The methodology involves mapping of joints in the field and laboratory testing of intact rock specimens to arrive at rock mass ...