Compressive strength is one of the mechanical properties of rock behavior. This study focuses on the Balikpapan and Kampungbaru Formations located in the Kutai Kartanegara area, East Kalimantan. The Schmidt Hammer testing method was applied due to the lack of previous studies utilizing this tool to evaluate rock hardness in correlation with compressive strength. The research site is situated in the Kutai Kartanegara area, specifically in the districts of Muara Badak, Muara Jawa, and Sanga-Sanga. Field observations revealed the presence of claystone slopes at predetermined locations. Based on the test results, the uniaxial compressive strength (UCS) values for the Balikpapan Formation range from 3.453 MPa to 5.454 MPa, while the Kampungbaru Formation ranges from 3.317 MPa to 8.571 MPa. The Schmidt Hammer rebound number (RN) values for the Balikpapan Formation range from 17 to 19.6, and for the Kampungbaru Formation from 15 to 23.7. A negative correlation was found between the rebound number and UCS, where higher RN values tend to correspond with lower UCS values. This is supported by the linear regression analysis showing a negative coefficient (-0.450).
 

In the Kutai Basin area, seasonal changes such as high rainfall can significantly increase groundwater content, so that the effect of water content on the shear strength of claystone, increasing water content in rocks tends to decrease shear strength. Water in the pores or fractures can increase pore water pressure and reduce effective normal stress. Shear strength is one of the most important mechanical parameters used to assess soil and rock stability, this parameter is very important in slope stability analysis, foundation planning, and various civil engineering and mining applications. Therefore, this study was conducted to determine whether the water content in rocks can affect the strength of rocks in receiving shear forces. The method used in this study is more quantitative and specific to the effect of water content on the shear strength of claystone in this area. Increasing water content in rocks tends to reduce shear strength. This study was conducted by taking claystone samples from several locations in the Kutai Basin. Data collection in the form of primary data and secondary data for testing physical properties and testing mechanical properties, in testing physical properties, the water content value will be taken as supporting data which is one of the factors that affect rock strength, in testing mechanical properties, claystone shear strength data will be taken. From the results of the physical properties test calculations, the air content in each Formation is obtained, namely, in the Kampungbaru Formation the minimum air content value is 15.54% and the maximum is 20.17%, in the Balikpapan Formation the minimum air content value is 10.21% and the maximum is 12,88%, in the Palaubalang Formation the minimum air content value is 10.49% and the maximum is 22.87%. The results of the strength of the claystone in receiving shear forces in the Kutai Basin are the Muara Jawa location 0.486MPa, Tanah Datar location 0.500 MPa, Sanga-sanga location 0.333 MPa, Muara Badak location 0.269, Air Putih location 0.711MPa, Mugirejo location 0.021 MPa and Lempake location 0.092 MPa.

Disposal area is an area at an open pit mine that is used as a place to store or dispose of worthless materials. Disposal must also follow the specified safety factor standards, if the disposal design is not safe after being analyzed by a geotechnical engineer, the design must be redesigned to achieve the desired safety factor value. One way to increase the fk value is to make a Counterweight plan in making disposal. Where Counterweight is a fill material that is made with special treatment so that the soil bearing capacity increases which functions to withstand the load on it. Landslides on disposal slopes are one of the serious problems faced in mining activities, especially in areas with vulnerable geological and topographic conditions. PT Jembayan Muarabara, which operates in Marangkayu District, Kutai Kartanegara Regency, East Kalimantan Province, is no exception to this challenge. The A–A’ cross section shows a safety factor value of 1.118 in saturated conditions, which indicates that the slope is at a stable limit and needs to be improved through engineering such as adding counterweights. The B–B’ cross-section has a safety factor value of 2.332, which is included in the safe category and has met the provisions of the ESDM Ministerial Decree No. 1827 K/30/MEM/2018. The C-C’ cross-section has a safety factor value of 1.511, which is included in the safe category and has met the provisions of the ESDM Ministerial Decree No. 1827 K/30/MEM/2018.

PT Ansaf Inti Resources is a company engaged in coal mining using the open pit method. In the process of mining in open pit mines, haul roads are indispensable in the process of transporting overburden and play an important role in the mining production cycle. The purpose of the study is to determine the total resistance to overburden production of the LGMG CMT96 conveyance based on the haul road segment that has been determined from the overburden loading point to the disposal of the material, then a calculation is made based on the standard number of good total resistance to the actual haul road. After calculating all segments of the haul road, the results of plotting the total obstacle graph against the speed, travel time, and production of the haul. So every 1% increase in total resistance will reduce the speed of the conveyance 1.346 km / h, while every 1% increase in total resistance will reduce the travel time of the conveyance 0.0464 minutes. The production results of the CMT96 conveyance before the improvement of the total obstacle to the road surface amounted to 55 lcm and 49 lcm, while after the improvement of the total obstacle to the road surface there was an increase in the production of the conveyance of 68 lcm and 62 lcm. So every 1% increase in total resistance will reduce the production of conveyance by 4.7429 lcm.