A comprehensive investigation was carried out to minimize the cost price of the rock fragmentation process including: drilling, blasting, secondary blasting and separating the large boulders (oversize rocks) while loading, until the optimized fragmentation, powder factor and ratio of burden (B) to blasthole diameter (?h) were achieved by doing several stages of drilling and blasting practically...

Rock strata in a coal mining environment are essentially bedded in nature and hence exhibit specific load-deformation characteristics. Mining may induce shearing as well as separation along the bedding planes which may result in bending and subsequent fracturing of the rock layer. This on the other hand may substantially change the in situ fluid flow properties of the rock mass, such as permeab...

Most of complex technical systems, including the rock cutting process, are very difficult to describe mathematically due to limited human recognition abilities depending on achieved state in natural sciences and technology. A confrontation between the conception (model) and the real system often arises in the investigation of rock cutting process. Identification represents determination of the ...

This paper derives the long-run marginal timber and sawing cost of producing lumber from a dual linear programming framework. A computational accounting procedure is suggested and compared with a recently designed procedure in industrial use. To be useful, the calculated cost figures should be approximately constant over a nontrivial interval of sales volumes. The preliminary results of a case ...

Analysis of advanced displacement in construction progress of tunnel excavation with weak surrounding rock is carried out by numerical method and comparison of model test result. In allusion to the problems of regional landslides and extruded large-deformation seriously impacting the stability of rock mass in construction process of large-section tunnel with weak surrounding rock, the elastic-p...