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Coulson Excavating Company, Inc. -Stroh Gravel Pit <br />Exhibit S -Permanent Nian-Made Structures <br />Background <br />One permanent man-made structure occurs within 200 feet of the permit azea. The <br />structure is an 8-inch diameter steel, high-pressure, liquids petroleum pipeline located <br />beneath the ground surface that runs through the project azea (see Exhibit C). An attempt <br />was made to come to an agreement with the owner of the pipeline (Kaneb Pipeline Co), <br />however Coulson would not agree to Kaneb's requested 50' setback and 3:1 slope. A <br />Geotechnical Stability analysis is presented here to show that a setback of 40' regardless <br />of slope is adequate to protect the pipeline. <br />Prior to any excavation, the exact location of the centerline of the pipeline will be <br />surveyed and flagged and a land surveyor will stake out the setback. <br />Analysis <br />Then slope stability analysis was performed through application of the GEOSYSTEM <br />Slope Stability Analysis program SB-SLOPE. Analysis was performed with a O.SH: 1 V <br />pit wall slope (see Figure 1). Table 1 summarizes the pazameters input into SB-SLOPE. <br />Table 1-Soil Physical Properties <br />Soil Density <br />(pefl* Cohesion <br />(~Sfl** Phi (~)** <br />Overburden (dry) 96 50 24 <br />Gravel (dry) 100 25 • 30* <br />Gravel (saturated) 134 0 35 <br />Weathered Claystone <br />(saturated) 115 0 14 <br />Intact Claystone (dry) 102 700 26 <br />* Budhu, Muni. 2000. Soil Mechanics & Foundations. New York: John Wiley & <br />Sons, Inc. <br />** Sorenson, Allen (Division of Minerals & Geology). 2002. Memo emailed to Peter <br />Wayland of Weiland Sugnet, Inc., Lakewood, CO. <br />• Estimated value. <br />Results and Conclusions <br />The slope analysis was run with the geometry input parameters given in Figure 1 and soil <br />properties given in Table 1. The model determined a safety factor of 1.04 with a failure <br />surface at 37 ft measured from toe of slope. Given the conservative soil property values <br />and an additional setback distance of 3 ft from the modeled, it is concluded that a 40ft <br />setback regazdless of slope is adequate to protect the Kaneb pipeline from damage or <br />movement. <br />