Rancangan Geometri Lereng Overall Sidewall pada Tambang Batubara Area Blok Mutiara PT. Singlurus Pratama Kabupaten Kutai Kartanegara Provinsi Kalimantan Timur

PT. Singlurus Pratama is a coal mining company located in Kutai Kartanegara Province of East Kalimantan. Located of mining area is divited into some Block, Sungai Merdeka Block, Argosari Block, Mutiara Block, and Margomulyo Block. Now, mining only done on the Sungai Merdeka Block stream free because others arestill in the stage of geotechnical study for done geotechnical, PT. Singlurus Pratama join with Mineral & Coal Studio. The Process schedule of geotechnical are taking a sample in the field, with drilling geotechnical rock properties testing in labs and analysis geotechnical in this case the author of a case study on geotechnical study to Block Mutiara location on the Block Mutiara mining plan represented by drill hole GT-04, GT-05 and GT-08. Input data for making model geotechnical use for dry density (γd) and saturated density(γd) result of physical testing, whereas cohesion (C) and friction angle in direct shear test results are valuable rest. Geotechnical modeling using program Rocscience Slide V6 assistance program with the limit equilibrium method. Geotechnical modeling single slope is done on a high 10 m angle 60°, while the overall slope modeling is done on a high 50 m, 60 m, and 70 m, angle 25°, 40°,45°, and 50° with properties meaning material of the entire drill hole. All of modeling put in dry soil water conditions half saturated and unsaturated. Recommendation of geotechnical the entire sidewall slopes in dry condition60 m high with an angle of 40°, condition saturated high 50 m and an angle 40° and condition saturated high 50 m and an angle 25°. Recommendation of geotechnical the entire based on the value of FK safe, FK≥1,20 for single slope FK≥1,30 for slope overall sidewall (Canmet, 1979). Based on the result of modeling the potential forlands slides on slopes overall sidewall is circular failure, because the material constituent slope is soft rock and the nature such as soil.