Investigation of deposits for traditional extraction activities (metals and coal) has generally been based on determining grade, or content, of the required material. In order to apply the grade concept to an ornamental rock such as slate, it is first necessary to define the variables that determine both the geotechnical recovery rate for the rock mass — which conditions the size of the extracted blocks – and the aesthetic features of the slate — which define the quality of the slabs as potential roofing material.
For this research, geotechnical and aesthetic data for a slate deposit were collected from 16 continuous core borehole samples. A fuzzy expert system was then developed using this data, defining the rock mass recovery rate and slab quality in accordance with the criteria of a slate expert, producing as a final output a zonation of the deposit in terms of top quality slate, medium quality slate or waste.
A mathematical model based on fuzzy logic was chosen due to the fact that the boundaries between different quality groups in a deposit are not clearly distinguished. Moreover, quality also depends on a company's infrastructures for transformation of the blocks, and also on its commercial strategies. 相似文献
A study has been done for analysing soil nailed cuts with circular type wedge failure by friction circle method. Various parameters
such as nail length, nail diameter, nail inclination, wall inclination and angle of internal friction of soil have been considered
to determine the factor of safety of nailed open cuts. The study shows that for cohesionless soil nailed cut, factor of safety
increase with increase of parameters like angle of internal friction of soil, length of nail (L) versus height of cut (H) ratio, cohesion of soil and nail inclination (upto 15°) with horizontal. The study revealed that nails grouted with cement
perform better than driven nails. A case study further confirms the analytical findings.
Received 7 October 相似文献
The application of steam-assisted gravity drainage (SAGD) to recover heavy oil sands is becoming increasingly important in
the northern Alberta McMurray Formation because of the vast resources/reserves accessible with this mechanism. Selecting the
stratigraphic elevations of SAGD well pairs is a vital decision for reservoir evaluation and planning. The inherent uncertainty
in the distribution of geological variables significantly influences this decision. Geostatistical simulation is used to capture
geological uncertainty, which is used can be transformed into a distribution of the best possible well pair elevations.
A simple exhaustive calculation scheme is used to determine the optimum stratigraphic location of a SAGD well pair where the
recovery R is maximized. There are three basic steps to the methodology: (1) model the uncertainty in the top continuous bitumen (TCB)
and bottom continuous bitumen (BCB) surfaces, (2) calculate the recovery at all possible elevation increments within the TCB
and BCB interval, and (3) identify the elevation that maximizes R. This is repeated for multiple TCB/BCB pairs of surfaces
to assess uncertainty. The methodology is described and implemented on a subset of data from the Athabasca Oilsands in Fort
McMurray, Alberta. 相似文献