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and rolling friction were initially derived from desktop literature review. The values were <br /> verified under a backanalysis on the west wall along trend of the January 2023 ground event. <br /> Input values were revised until the rockfall runout and energy resembled that of the ground <br /> event, correlated to topographic data of the rockfall debris field. Summary of slope input <br /> parameters is provided in Table 3. <br /> Table 3. Rockfall Simulation Input Parameters <br /> Material Normal Tangential Dynamic Rolling <br /> Restitution(Rn) Restitution (Rt) Friction Friction <br /> Mean 0.32 0.71 0.55 0.15 <br /> Leadville <br /> Limestone Standard <br /> 0.04 0.04 0.04 0.02 <br /> Deviation <br /> Mean 0.32 0.71 0.55 0.30 <br /> Interbed <br /> Material Standard <br /> 0.04 0.04 0.04 0.04 <br /> Deviation <br /> Damping was disabled for viscoplastic and forest & vegetation. Slope roughness parameters <br /> were set to 0 degrees because roughness is already accounted for by the detailed slope <br /> geometry used in the model. Three rock types were used with increasing size and mass to <br /> mimic the January ground event.The rigid body method was used to allow definition of rock <br /> size, mass and shape. The 1) Small (2022 Ibm), 2) Medium (20,227 Ibm), and 3) Large (93,642 <br /> Ibm) blocks were assigned square, pentagon and rhombus shapes to simulate the ground event <br /> blocks. <br /> Computational modeling was completed with a linear seeder point at the top of the upper <br /> limestone bed with a minimum of 3,000 rocks simulated. A crest loss of the overhanging <br /> limestone bed was induced to remove that geometry at point of rockfall initiation to maximize <br /> the translational velocity. Detailed results on the distribution of bounce height, velocity, and <br /> impact forces for each run were obtained by locating data collectors along the slopes.Those <br /> results were used to evaluate appropriate berm height, setback from the slope toe, and <br /> determined total energy impacting the berm. <br /> ROCKFALL MITIGATION RECOMMENDATIONS <br /> Based on the results of the extensive rockfall modeling along the West face and multiple East <br /> face transects, the following recommendations and descriptions of rockfall treatments are <br /> provided below. <br /> Page.8 <br /> 535 16th STREET,SUITE 620 1 DENVER,CO 80202 1 (303)732-3692 1 WWW.KILDUFFUNDERGROUND.COM <br />