Laserfiche WebLink
I ! ► ! I I <br /> I ► I i I t <br /> N <br /> i <br /> 1 1 i I <br /> I ! ► � I i I <br /> I 1 i ,� ► i i <br /> S ) W�NN <br /> i <br /> I I I CL ► ! I <br /> ► f t a I I I <br /> 1 I ! 1 <br /> I 1 1 I t t <br /> ! 1 I f I I <br /> ► I i I t I <br /> � 1 <br /> t 4 I�WORKING T I <br /> NF j FACE {fu <br /> i <br /> ! x xz I 1 0 1 ► N I <br /> I X v it ! i '- I 1 , 4 ! <br /> J O RWJ I 1 I ( .�.QW I <br /> a 3xU I 1 Fax I i a Ioa t <br /> WORKING r2w <br /> _ '-5s.o_Fr FACE— ► 1 , i ►o w o w f <br /> a-H: ' <br /> _ <br /> 33A, '•'� Lj J 2' 3 2 Cam) 1 )L I I <br /> —J <br /> Figure 10. Previously submitted mine plan by Environment, Inc. showing utilization of <br /> unnecessary room and pillar roof support design. Image is replicated as a relict on the attached <br /> Gallery Map. <br /> A maximum room design was calculated for three pillar designs and the safety factor was <br /> calculated for design as submitted to the DRMS (Table 2; Figure 11). All designs meet or <br /> exceed NIOSH's design guidelines of a safety factor of 4.0 (Esterhuizen et al., 2011). The <br /> maximum span between pillars is a function of the cross-sectional size of a pillar, the strength of <br /> the rock contained within the pillar, and the weight of the rock mass supported by the pillar. The <br /> equation used to design pillars in the study and data generated for pillar design is found in <br /> Appendix 3. The safety factor is the ratio of the stress induced by the rock above the pillar to the <br /> ability of the pillar to hold the stress. <br /> Rose Red Quarry Geotechnical Report 16 <br />