BANDUNG - Over the past decade, the coal industry has played a significant role in supporting national development. The coal mining sector supports development in various regional/national economic sectors by contributing to state revenues, entering foreign exchange through exports, and supporting electrification and national energy security. The coal mining sector's contribution to state revenue comes from paying taxes, including royalties. In addition, the role given is to create jobs. 

PT. Pamapersada Nusantara (PAMA) is one of the largest coal mining contractors in Indonesia with its worksite at PT. Bukit Asam Tbk in Tanjung Enim, South Sumatra. 

One of the sites carried out by PAMA is the MTBU Site. At this MTBU district mine, PAMA appointed PT Nur Straits Engineering (NSE) as the planning consultant to carry out a Detailed Engineering Design (DED) on the foundation structure of the coal crusher and analysis of mine slope stability in the plan to make operational bulkheads at the MTBU Pit. 

At the beginning stage of the planning, a soil investigation survey was carried out by conducting four deep drill points with SPT test within 2 m intervals, 6 CPT points, 4 points in the coal crusher area, and 2 points in the operational bulkhead area. In addition, disturbed samples (DS), undisturbed samples (UDS), and intact rock were also taken. 

Soil mechanics laboratory testing was carried out at the NSE soil laboratory located in the city of Bandung. 

Based on the soil investigation area, the design parameters of the coal crusher area will be divided into two, namely, zone 1 coal crusher foundation and zone 2 slope stability and retaining walls. There are 5 (five) types of structures to be planned in the coal crusher area, namely hopper, tower, conveyor 01, conveyor 02, and conveyor 03. 

Based on the results of shallow foundation analysis, that is shallow foundations can support all structural columns. Yet, several columns recommend using pile foundations to minimize deformation due to large loads on the vertical (axial load) or horizontal (lateral) axis. 

The slope stability analysis was carried out with undrained states, which modeled short-term conditions and drained states, which modeled long-term conditions. Based on the topographic data for the coal crusher slope and the results of the NSE soil investigation, the coal crusher slope that PAMA has constructed meets the slope stability criteria. 

With NSE's involvement in this planning work, it can be said that NSE has penetrated the mining industry and participated in advancing the national economy.