Laserfiche WebLink
Cross Sections 1, 2 and 3 are the critical ones for the CR81 Road. Cross Section 1 is the worst <br /> case since it is the highest and longest cross section that is closest to the road. <br /> The following information was extracted from the Newfields Report of December 9, 2016: <br /> Stability analyses were performed using the computer program SLIDE 6 by Rocscience for static <br /> and pseudo-static conditions. SLIDE is a two-dimensional slope stability program for evaluating <br /> circular or noncircular failure surfaces in soil or rock slopes using limit equilibrium methods. <br /> Spencer's procedure, which is applicable for all slope geometries and soil profiles, was utilized <br /> within the stability model and assumes all inter-slice forces are parallel and have the some <br /> inclination. <br /> Minimum acceptable factors of safety(FOS)for static and pseudo-static conditions were based <br /> on criteria established by the Colorado Department of Reclamation, Mining, and Safety(DBMS), <br /> as follows: <br /> - Exterior, eastern aspect slopes are be considered "critical"as slope failures could impact <br /> off-site areas, and as discussed in Section 3.2 the strength characterization of the materials <br /> within ECOSA is considered robust. Based on these attributes, the minimum acceptable <br /> factors of safety are 1.3 and 1.15 for static and pseudostatic conditions, respectively. <br /> - Interior, western aspect slopes are considered "non-critical"and the associated minimum <br /> acceptable factors of safety for these slopes are 1.25 and 1.1 for static and pseudostatic <br /> conditions, respectively. <br /> The peak ground acceleration used was .035g and 0.11 g, for the 475-year and 2,475 year return <br /> seismic events, respectively, which is conservative. Colluvium strength was also reduced by 20% <br /> for the accounting of seismic events. <br /> 13 <br />