In this work, the effect of rock bolt angle on the shear behavior of Rock Bridges is investigated using the particle flow code in two dimensions (PFC2D) for three different Rock Bridge lengths. Firstly, the calibration of PF2D is performed to reproduce the gypsum sample. Then the numerical models with the dimensions of 100 mm * 100 mm are prepared. The Rock Bridge is created in the middle of th...

Stability of the retained goaf-side gateroad (RGSG) is influenced mainly by the movements of the roof strata near coal seam after coalface passes by. To make effective controlling technology for the stability of the RGSG, we analyze the roof structure over the RGSG to illustrate the mechanism causing the RGSG instability under different roof conditions. We then examine the dynamic evolution of ...

The primordial earth surface exposed minerals comprised mainly of carbonates, silicates and smaller amounts of phosphates. Weathering eventually led to the dissolution of the surface rock and the leaching of their components into the rivers, lakes and oceans. There, complex chemistry depending upon the temperature, pH, pressure, and atmospheric carbon dioxide content led to the reprecipitation ...

This study investigated whether spatial learning ability and cue use of gobies (Gobiidae) from two contrasting habitats differed in a spatial task. Gobies were collected from the spatially complex rock pools and dynamic, homogenous sandy shores. Fishes were trained to locate a shelter under the simulated threat of predation and it was determined whether they used local or extra-maze (global) an...

The formation of large tin-tungsten (Sn-W) deposits around granitic intrusions requires the circulation volumes fluids within permeable structures. Half world’s tungsten production originates from highly mineralized veins above and altered part granite (the greisen), whose results intense fluid-rock interactions. During greisenization processes, mineral reactions involve a decrease in rock volu...

No prior research has documented the different types of rock coatings in Yosemite Valley, despite the evident black streaks down Yosemite Falls, the light granitic rock exposed by recent rock falls contrasting with dark rock coatings, and the millions of visitors who have photographed the coated rocks of Yosemite. This paper identifies the types of rock coatings found on Half Dome, in Yosemite ...

Three computer models of varying complexity were developed in order to investigate the kinematics, kinetics, muscle operating ranges, and energetics of rock climbing. First, inverse dynamic models were used to investigate the joint angles and torques used in climbing and to quantify the total mechanical work required for typical rock climbing. Climbing experience was found to have a significant...

Neuro-fuzzy inference systems have been used in many areas in civil engineering applications. A stability assessment model for epimetamorphic rock slopes has been developed by using Adaptive Neuro-Fuzzy Inference System (ANFIS) for its capacity of dynamic nonlinear analyses. In the present study the inference system is employed to predict the stability of the slope by choosing bulk density γ, t...

Introduction: We have completed analysis of a new near-field rock count at the Mars Pathfinder landing site and determined that the previously published [1,2] rock count suggesting 16 % cumulative fractional area (CFA) covered by rocks is incorrect. The earlier value is not so much wrong (our new CFA is 20%), as right for the wrong reason: both the old and the new CFA’s are consistent with remo...