The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were per...

there are limitations in experimental studies on sand-gravel mixtures due to the small size of testingspecimens. due to this problem, many researchers have worked on prediction of the shear strength of mixture by testingthe sandy fraction of soil alone and developed empirical relationships. most of the previous relationships have beendetermined for low surcharge pressures in which particle brea...

Analytical buckling models are important for down-hole operations to ensure the structural integrity of the drill string. A literature survey shows that most published analytical buckling models do not address the effects of inclination angle, boundary conditions or friction. The objective of this paper is to study the effects of boundary conditions, friction and angular inclination on the heli...

The iron content of the ore used is crucial for the productivity and coke consumption rate in blast furnace pig iron production. Therefore, most iron ore deposits are processed in beneficiation plants to increase the iron content and remove impurities. In several comminution stages, the particle size of the ore is reduced to ensure that the iron oxides are physically liberated from the gangue. ...

Inspecting the behavior of the rockfill materials is of significant importance in analysis of rockfill dams. Since the dimensions of grains in such materials are greater than the conventional sizes suitable for soil mechanics tests, it is necessary to experimentally study them in specific large-scale apparatuses. In this research, the behavior of rockfill materials in two large rockfill dams co...

This paper aims to study the mechanical behaviour and failure mechanism of intact rocks under different loading conditions using the grain based model implemented in the universal distinct element code (UDEC). The grain based numerical model is a powerful tool to investigate complicated micro-structural mechanical behaviour of rocks. In the UDEC grain based model, the intact material is simulat...

There are various parameters that affect stability and expansion of failure zones in under pressure tunnels. Among the important parameters that affect failure zones around the tunnels are cohesion and internal friction angle of the rock mass. In addition, the cross sectional shape is the considerable point in failure distribution around the tunnels. The stress analysis method is one of the app...

this paper presents a simplified approach to estimate the resultant force, which should be provided by a retention system, for the equilibrium of unstable slopes. the results were obtained with a developed algorithm, based on limit equilibrium analyses, that assumes a two-part wedge failure mechanism. design charts to obtain equivalent earth pressure coefficients are presented. based on the res...

inspecting the behavior of the rockfill materials is of significant importance in analysis of rockfill dams. since the dimensions of grains in such materials are greater than the conventional sizes suitable for soil mechanics tests, it is necessary to experimentally study them in specific large-scale apparatuses. in this research, the behavior of rockfill materials in two large rockfill dams co...