Small samples of rock, like those used in laboratory collision experiments, are known to be much stronger than bodies that are meters to hundreds of meters in size [1]. Specifically, the impactor energy per unit target mass needed to shatter the target decreases dramatically with increasing target size. This occurs because the strength of rock, like many other geological materials, depends stro...

Despite evidence that weathering plays a role in forming intertidal, estuarine, and fluvial rock platforms, many publications uncritically refer to “wave-cut” or “stream-cut” rock platforms. The alternative explanations of chemical weathering and physical water erosion of rock platforms have been debated since 1839. Our new approach to this long-standing problem introduces data from fluvial as ...

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...

In order to solve the bit front rake angle parameter selection problem of under different coal rock, it is proposed in polycrystalline diamond compact no core bit as the research object, and established a bit compact two-dimensional stress model of cutting teeth. The result shows that the front rake angle is the factor of cutting force and the drilling efficiency. Application of Solid Works sim...

The dynamic response mechanism of the rock fragmentation and its influential factors by TBM disc cutter are studied in this paper. Firstly, a dynamic response model is established based on the fracture mechanics and finite element theory. Secondly, a fragmentation rule is founded according to the dynamic response model, and then numerical simulations for dynamic response of rock are carried out...

RMR, Rock Mass Rating, is one of the famous rock classifications. However, RMR was proposed empirically and absolutely depends on the experience of engineer. Therefore, engineering verification is needed for RMR system itself. In this study, the factor analysis and the multiple regressions were performed in order to evaluate the validity of rating factor of RMR. Also numerical analysis was carr...

The calcarenites carbonate rocks of the Quaternary ridges, which extend along the northwestern Mediterranean coastal plain of Egypt, represent an excellent model for the transformation of loose sediments to real sedimentary rocks by the different stages of meteoric diagenesis. The depositional and diagenetic fabrics of the rocks, in addition to the strata orientation, highly affect their ultima...

Recent work at the Underground Research Laboratory of Atomic Energy of Canada Limited in Pinawa, Manitoba, has shown that high compressive stresses near the tunnel face significantly contribute to the loss of strength, and eventual failure of the rock, through stress-induced brittle fracturing. A program of laboratory testing has been undertaken to investigate the effects of brittle fracture on...

We have carried out a series of laboratory experiments on AE monitoring to investigate the fracture behaviour of some dry and water-saturated rock samples of south-east Gujarat and Maharashtra which have been experiencing prolific seismicity in recent years in India. The results obtained from the study of Pavgadh rhyolites and Godhra granites tested to failure under triaxial compression are pre...

A rock failure criterion is very important for prediction of the ultimate strength in rock mechanics and geotechnics; it is determined for rock mechanics studies in mining, civil, and oil wellborn drilling operations. Also shales are among the most difficult to treat formations. Therefore, in this research work, using the artificial neural network (ANN), a model was built to predict the ultimat...