Laserfiche WebLink
INTRODUCTION <br />Geotechnical logging, testing and results evaluation for <br />the Coal Ridge No. 1 Mine, Garfield County, Colorado are the <br />subjects of this report. Mr. Sam S. Arentz III, Vice President- <br />Operations, Storm King Mines, Denver, Colorado authorized its <br />undertaking. <br />Storm King Mines(STORM KING) is in the process of planning <br />the first hydraulic coal mining operation in the U.S.A., which <br />would be the proposed Coal Ridge No. 1 Mine. The investigation <br />includes, among other things, the drilling and evaluation of <br />drill cores from several core holes. In addition to quantity <br />and quality data, STORM KING desires to have a geotechnical <br />data base established for roof, coal, interburden and floor <br />materials associated with the Upper Wheeler Seam(Main Wheeler <br />Seam) and the Lower Wheeler Seam. Further, they desire to have <br />the geotechnical characteristics of a continuous(from collar to <br />total depth) core hole specified for use in future subsidence <br />studies. Toward that end, Seegmiller International(SEEGMILLER) <br />was asked to perform a geotechnical study on drill cores from <br />two holes, Drill Holes 3.75 and 8A• Hole locations are shown in <br />Figure 1. The study involved detailed geotechnical logging and <br />• laboratory physical properties testing. The present report is <br />the culmination of the SEEGMILLER geotechnical study. <br />The basic purposes of the study and this report are [1] <br />produce geotechnical logs and strength magnitude data for roof, <br />interburden, floor and coal materials, [2] determine the signif- <br />icance of that geotechnical data as they pertain to future mining <br />and (3] produce geotechnical characteristic logs for the continuous <br />drill core for use in future subsidence studies. This study and <br />report are limited to an analysis of core from only two drill <br />holes and to the tests which could be performed. Changes in <br />physical properties could exist and the limited testing may not <br />adequately evaluate the true strength magnitudes. Sources of <br />information for the study include geologic information from and <br />discussions with STORM KING personnel involved in the total <br />project. <br />This report begins with a discussion of the geotechnical <br />core logging and corresponding results. The rock testing pro- <br />cedures are then presented and are followed by the statistical <br />analysis of results. Engineering design parameters are recom- <br />mended and the significance of study results, in terms of prob- <br />able future ground control conditions, are outlined. The detailed <br />geotechnical logs, laboratory test results and triaxial test plots <br />are appended. <br /> <br />SEEGMILLER INTERNATIONAL <br />