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K jL U UFF � RM R Aggregates, Inc. <br /> u N o E R G R O u N Rock Failure Analyses and Stabilization Report <br /> EN GI N E ER I N G. IN C Mid Continent Limestone Quarry <br /> A site mapping program was performed to collect structure data on the West wall and to determine <br /> the north limit of the upper limestone beds as they pinch out upslope. The bed thickness and bedding <br /> dip of the two upper limestone beds decreases to the north from the quarry headwall as the forelimb <br /> of the monocline rolls over toward the fold axis. Kirkham et al. map the upper limestone beds as <br /> dipping between 38 degrees near the quarry to 24 degrees toward the top of the hill to the north, <br /> which forms dip slopes and tends to control hillside slope topography. <br /> _ The July 2023 site reconnaissance mapped the upper limestone beds from near the ground <br /> event and northward as the beds pinch out and bedding decreases to approximately- <br /> Appendix F photos document the beds decreasing in thickness at points along the slope. Locations of <br /> bedding dip and dip direction on the top of the massive limestone (contact with the upper limestone <br /> units) and measurement of the presence/thickness of the upper limestone beds are designated on <br /> Figure 3 (provided by Lewicki & Associates) with corresponding site numbers, detailed below from <br /> south to north: <br /> Photos of the site locations are provided in Appendix F. Talus cover and the waviness of the bed <br /> surface limited the ability for high confidence structural measurements at some sites. <br /> The spatial intent of the slope configuration models discussed in section 6 should be to extend north <br /> to where the upper limestone layers pinch out above the current mining activities. The bedrock <br /> bedding slope, which is the boundary between the massive limestone below and the adverse <br /> limestone units above, was observed as very laterally continuous but could undulate locally creating a <br /> slight change in dip direction. To meet the established minimum FO5 for the slope, using a bench <br /> slope geometry of 1.4H:1V or greater that leaves varying thicknesses of the upper limestone layers in <br /> place will likely require the use of mechanical stabilization.This is considered a lesser option for long- <br /> term stability and safety but is considered below on an as needed basis. <br /> Page 14 <br /> 535 16"STREET,SUITE 620 1 PENVER,CO 80202 1 (303)732-3692 1 WWW.KILDUFFJNDERGROUND.COM <br />