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Slope stability is a key concern in open-pit mining due to its impact on safety and operational efficiency. Mine X, located in Kalimantan Island, faces landslide risks on its high wall slopes. This study aims to model slope stability and determine safe and economical slope geometry. The analysis was performed using the Limit Equilibrium Method (Bishop Simplified), both analytically and numerically, through Slide 6.0 software by Rockscience Inc. Input data were obtained from five geotechnical investigation points provided by PT.X, including cohesion, internal friction angle, and saturated unit weight. Two lithologies were analyzed—claystone and sandstone—with slope height variations (5 m, 10 m, 15 m) and angles (26°, 45°, 51°, 59°), under dry and saturated conditions. Simulation results show that the factor of safety (SF) decreases with increasing slope height and angle, especially under saturated conditions. Sandstone demonstrates better stability than claystone. The recommended optimal slope geometry is 10 meters in height with a 59° angle, yielding a SF ≥ 1.25 and aligning with the PC-400 excavator's cutting capability. This study provides a technical reference for designing safe slopes that support mining productivity.

Rock stability and service life in geotechnical and mining engineering are highly dependent on the rock's mechanical and physical parameters, where the variation in sandstone grain size is a crucial intrinsic factor. This study aims to comprehensively analyze the correlation between sandstone grain size with uniaxial compressive strength (UCS) and resistance to weathering (Slake Durability Index) in samples taken from the Balikpapan and Pulau Balang Formations in the Samarinda area, East Kalimantan. The research methodology involved a series of standard laboratory tests, including rock physical properties analysis, grain size distribution analysis, UCS testing, and slake durability testing through three cycles. The test results show a significant correlation: sandstone with finer grain sizes and higher density consistently demonstrates greater UCS values and a higher Durability Index, indicating superior mechanical and physical resistance. Specifically, the Pulau Balang Formation exhibits a more compact structure and finer grain size, resulting in better durability values compared to the Balikpapan Formation. These findings are important as a geomechanical data basis for slope design planning, rock mass stability analysis, and material selection in infrastructure projects or mining operations involving both formations.

The purpose of this study was to determine the effect of pulley angle variations of 13.5ᵒ and 14ᵒ and roller weight variations of 12 g, 14 g, and 16 g on the torque of a 150 cm3 automatic motorcycle. The method with a quantitative approach the method used is the experimental method. For the sample of this research is a type of pulley and 3 types of rollers with different slopes and weights where the angle varies to test the 150 cm3 matic motorcycle torque used. From the results of this study results in a value where the Fcount value is greater than the Ftable means that the null hypothesis (H02) is rejected and the alternative hypothesis (H22) is accepted or the mass of the roller has an influence on torque, the Fcount value is greater than the Ftable means that the hypothesis (H01) is rejected and the alternative hypothesis (H11) is accepted or the mass of the roller has an influence on torque, and that the interaction between pulley angle and roller mass does not affect, and the Ftable value is lower than the Fcount value that the hypothesis (H03) is accepted and the alternative hypothesis (H33) is rejected, roller mass affects torque.

This study examines the reclamation plan of PT. Z for the 2023–2027 period with the aim of assessing the technical feasibility, ecological effectiveness, and alignment with national reclamation regulations. A descriptive-quantitative approach was employed through field observations, analysis of geomorphological conditions, evaluation of topsoil management, assessment of revegetation performance, and review of key environmental documents. The planned land disturbance reaches 138.53 ha, with reclamation focused on the disposal and topsoil areas covering 29.67 ha, as the mining pit remains active. Reclamation activities include land recontouring, topsoil spreading, erosion control, establishment of Legume Cover Crops (LCC), and planting of local species such as Rukam. The results indicate that the implemented strategies effectively enhance soil stability, improve vegetation cover, and support ecosystem recovery. Furthermore, the reclamation program meets the key performance criteria set by the Ministry of Energy and Mineral Resources, with vegetation cover exceeding 90% and stable slope conditions. Challenges remain, particularly related to sedimentation management and the absence of pit reclamation during the active mining phase. Overall, the study concludes that PT. Z has developed and executed a reclamation plan that reflects good mining practices and environmental stewardship, contributing to the long-term sustainability of post-mining land use.

Kaloran Village is an area characterized by steep slope topography that makes it vulnerable to landslides, especially during the rainy season with high rainfall intensity. Although the landslide risk level in this village is still relatively low and has never caused any casualties, the potential for material losses and psychosocial impacts that may arise still need to be seriously anticipated. Disaster risk reduction efforts in Kaloran Village are carried out through the Disaster Resilient Village Work Program (Destana), which aims to increase the capacity and capability of the community in facing disaster threats. The program implementation method consists of three main stages: preparation through focus group discussions (FGDs) and interviews with stakeholders, preparation of the Destana document containing mitigation strategies and steps, and community empowerment through socialization activities and preparedness training. The results of the study indicate that Kaloran Village is categorized as a Medium Resilient Village with a resilience score of 68.97. This achievement serves as an important basis for strengthening the village preparedness system, which is followed up with the establishment of the Disaster Risk Reduction Forum (FPRB) "Kaloran Tangguh Rescue" as a community coordination forum. In addition, evacuation route maps were produced, which serve as technical guidance in the event of a disaster, and the development of the Destana (Disaster Preparedness and Disaster Management) and Contingency Plan (Renkon) documents, which serve as official guidelines for disaster mitigation and management efforts at the village level. This program demonstrates that active community participation, collaboration between stakeholders, and the development of strategic documents can strengthen village preparedness for the threat of landslides.

Lau Kawar Lake, a natural tourism area located on the slopes of Mount Sinabung in Karo Regency, North Sumatra, holds significant potential for the development of nature and culture-based tourism. However, the growth in tourist visits has not yet met expectations due to limited accessibility across various dimensions. This study aims to formulate strategies for improving physical, informational, and institutional accessibility in support of sustainable regional development.The research adopts a mixed methods approach, emphasizing primary data collection through field observations, interviews with key stakeholders and village officials, as well as surveys of 60 tourist respondents. Findings reveal that, overall, the three dimensions of accessibility are still rated as "fair," with average scores ranging from 3.28 to 3.36. The main barriers identified include inadequate road infra-structure within the area, lack of dedicated public transportation for tourists, limited official digital promotional content, and weak institutional coordination in area management. A synthesis of the quantitative and qualitative results indicates that the development of Lau Kawar Lake requires an integrative approach that combines spatial planning, community-based governance, and local policy interventions.Based on these findings, several strategic recommendations are proposed: (1) improvement of access roads and landslide-prone areas through Special Allocation Fund (DAK) for infrastructure; (2) provision of dedicated public transportation for tourists with fixed routes and schedules from the nearest city center; (3) installation of directional signs and visual information boards in aesthetically pleasing formats and bilingual language; (4) establishment of a Digital Promotion Team involving local actors and institutions; (5) capacity-building programs for the community in tourism services, home stay management, and culinary entrepreneurship; and (6) formation of a Cross-Sectoral Accessibility Coordination Forum for Lau Kawar Tourism as a medium-term planning and monitoring platform.This study contributes contextually to strengthening the accessibility dimension as a key prerequisite for advancing local tourism destinations towards sustainable, inclusive, and locally grounded development.

Durability is defined as a measure of a rock's resistance to weathering and disintegration when the rock undergoes weathering processes over a short period of time. The susceptibility of rocks to disintegration is related to their low durability. Rock durability is often measured using the slake durability test. The slake durability test is widely used to assess physical changes resulting from wetting-drying processes (Franklin and Chandra, 1972). Therefore, slake durability testing is conducted to understand the weathering of rocks caused by heat and water, particularly clay stones which are one of the constituent rocks on a slope. The sampling location is around Sanga-sanga and Muara Badak. Sampling was conducted with coordinate points and the Balikpapan and Kampungbaru formations. The claystone samples taken were then brought to the Mineral and Coal Technology Laboratory of the Engineering Faculty of Mulawarman University for Slake Durability tests. In this study, the lowest index value obtained was 45.7% and the highest value was 93%, indicating high to very high durability. The difference in the durability index values of claystone at the research locations indicates the presence of variables that can affect the slake durability index values of the claystone in the Balikpapan and Kampungbaru formations, including grain size and mineral content as well as geological conditions at the research site. Based on the results of the claystone durability tests, the durability index value (Id2) was obtained, indicating that the sandstone at the research location falls into the classification of high to low.

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.

A landslide that occurred on May 24, 2024, in Pekon Datarajan, Ulubelu District, Tanggamus, Lampung, caused significant disruption to provincial road access and resulted in material losses. This study aims to assess the post-failure slope stability through field geotechnical investigation and numerical analysis using the Limit Equilibrium Method (LEM), and to propose immediate countermeasures. The slope materials consist of MH (inorganic silt) and ML (elastic silt) with high moisture content and moderate to high swelling potential. The lithology is dominated by montmorillonite clay, which has hygroscopic characteristics, making it highly vulnerable to water infiltration that reduces shear strength and increases the risk of slope failure. Stability analysis indicates a post-failure factor of safety (FoS) of 1.36 (static loading) and 1.03 (dynamic loading), which decreases to 1.07 beneath raised groundwater conditions. Recommended immediate mitigation includes surface runoff control, the construction of impermeable drainage systems, the sealing of cracks using impermeable materials, and the installation of temporary slope reinforcements such as sheet piles. The implementation of these measures increased the FoS to 1.61 (static loading) and 1.16 (dynamic loading). This study provides a technical basis for the rapid and effective mitigation of landslides in areas with similar geological and hydrological conditions.

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.

Putra Muba Coal is one of the subsidiaries under the MNC Group, operating in the coal mining sector with an IUP (Mining Business Permit) area covering 2,947 hectares. During its mining operations at the Pandu Pit, PT. Putra Muba Coal experienced a landslide incident on the highwall side. Therefore, a back-analysis using the deterministic method was conducted to determine the material property values that led to the slope failure in the mining area. The slope material consists of claystone and siltstone layers, each with a cohesion value of 192.3 kN/m² and 157.0 kN/m², and internal friction angles of 25.3° and 24.4°, respectively. Based on the back-analysis results, it was found that there was a decrease in material property values, with cohesion reduced by 91% and the internal friction angle reduced by 29%. This reduction in material properties suggests that the decrease in cohesion was the primary factor causing the highwall slope failure, as indicated by the back-analysis of slope stability which resulted in a safety factor of (SF = 1.008).

Landslides or commonly called landslides are a disaster that often hits areas with tropical climates. The damage caused by landslides is most dominantly structural damage such as damaged road sections that are cut off. At the research location, there was a landslide that resulted in the obstruction of the road flow which was originally two lanes to one lane, it is feared that landslides will occur again, so one of the landslide prevention techniques is to use retaining walls. Based on this, this study is deemed necessary to determine the slope safety factor and to determine the safety of the slope after using retaining walls. The purpose of this study was to determine the level of slope safety without being given a load, the level of slope safety after being given a load of 25 Kpa and the level of slope safety after being given a load of 25 kpa and the addition of a retaining wall on the research slope using a Retaining Wall. In this study using the Finite Element Method in the calculation to find the level of safety of a slope, the researcher used the help of Plaxis 2D V20 Software, and the results of the calculation obtained a slope safety factor of 1.31, after being given a load of 25 kpa the slope safety factor was 1.14 and after being given a retaining wall the slope safety factor increased to 2.46.

Slope failure can occur even though slope design and reinforcement have been carried out. However, before it completely collapses, there are often signs from the slope. These signs should be carefully observed through slope monitoring or surveillance activities to provide advance warnings regarding the development of slope instability, allowing mitigation measures to be implemented to reduce or avoid the impacts of instability, as well as to predict the timing of landslides using Inverse Velocity. This study was conducted at the PIT of PT Fajar Sakti Prima in East Kalimantan Province. Observations were carried out over 39 days to obtain deformation behavior, velocity values for mitigation actions, and inverse velocity values to predict the timing of landslides. In this observation, the deformation behavior values at PM 01, PM 02, and PM 03 were initially linear, then exhibited progressive behavior on November 7-8, 2024. The predicted landslide timing from this observation was November 20-21, 2024. Based on velocity values correlated with the TARP, critical categories were obtained at 7.40 - 9.86 cm/day and very critical at >26.17 cm/day

Mining with an open pit system is carried out by excavating and removing the overburden to obtain coal. However, before mining, it is important to obtain geotechnical data information. As well as the lithology of the rocks below the surface, it is necessary to carry out geotechnical drilling (full coring). This study can determine the value of slope geometry safety factors and plan safe slope geometry, both individual slopes and overall slopes. Therefore, this was done to determine the influence of GSI geotechnical parameters on the value of static and dynamic slope safety factors. The method used in determining the safety factor and the probability of an avalanche is the Morgenstern-Price boundary equilibrium method with the Generalized Hoek-Brown collapse criterion in static and dynamic slope conditions. The input parameters used in the analysis were natural density, compressive strength value (UCS), geological srength index (GSI), disturbance factor (D), intact rock constant (mi), as well as seismic load factor, and groundwater level. The optimal geometry on the Highwall slope is the configuration of the Highwall slope with a height of 74 m and an angle of 23°, supported by a single slope of 5-10 meters, a berm of 7 meters with an angle of 40°. Seam D Claystone lithology with GSI 50, Siltstone with GSI 70, Sandstone with GSI 70, and Seam E Claystone lithology with GSI 50, Siltstone with GSI 40, Sandstone with GSI 75.Can be applied within a safe limit where FK Static 1.7 PK Static 0% and FK Dynamic 1.4 PK Dynamic 6%.

Tuna fish (Thunnus albacares) is a fish that has a fairly high economic value and is the dominant catch landed at PPS Nizam Zachman which comes from the WPPNRI 573. Based on the high production results and fishing activities, it is necessary to analyze the utilization level that has been carried out by PPS Nizam Zachman in the WPPNRI 573 for the sustainability of tuna fish (Thunnus albacares). This study aims to determine the CPUE (Catch per Unit Effort), sustainable potential (MSY), utilization level and effort level of tuna fish (Thunnus albacares) landed at PPS Nizam Zachman. This study was conducted on 18 until 30 November 2024. The method used in this study is the Schaefer surplus production method approach. Tuna (Thunnus albacares) were caught using handline fishing gear, purse seines, and tuna longlines. The standard used as the FPI (Fishing Power Index) is the highest CPUE value, namely purse seines. Based on the analysis using the Schaefer model, the intercept value (a) shows 30.864 and the slope (b) is -16.458. The intercept value shows that if there is no fishing effort, the potential for tuna (Thunnus albacares) in WPPNRI 573 available in nature is still 30.864 tons/trip. The MSY catch was 14,469,702 tons, the optimum effort was 938 trips, and the allowable catch was 11,575,762 tons with an average utilization rate of tuna (Thunnus albacares) in WPPNRI 573 landed at PPS Nizam Zachman of 92% with an average effort rate of 106%. This shows that the utilization rate of tuna (Thunnus albacares) in WPPNRI 573 landed at PPS Nizam Zachman is in a dense catch condition.

The increasing population triggers a demand for land for housing and other activities. Along with this, issues arise regarding the limited availability of land, especially in rapidly developed areas. This limitation has the potential to create an imbalance between the growing need for space and the existing land capacity. This study evaluates the land carrying capacity in four sub-districts in the southern part of Medan City, namely Medan Tuntungan, Medan Johor, Medan Amplas, and Medan Denai, in dealing with the continuously growing population. Using a spatial analysis approach with ArcGIS 10.8 software and detailed spatial data, this research identifies potential areas for residential development and projects the capacity of land to accommodate future populations. The analysis covers physical and environmental aspects such as land slope, soil type, natural disaster risks, and access to public facilities. The results show that each sub-district has different potentials and challenges. Medan Tuntungan, with its large area and flat land conditions, shows significant potential for residential development, although attention must be given to the existence of protected areas and agricultural land that must be preserved. Medan Johor, as an economic center, faces substantial pressure on land use, with some areas nearing their maximum capacity. Medan Amplas and Medan Denai, which are more urban, experience stricter land limitations. Population growth projections indicate a significant increase in land demand in some sub-districts in the coming decades. Without effective management, this has the potential to exert high pressure on the environment and urban infrastructure. This research emphasizes the importance of spatial planning and sustainable development policies to maintain a balance between housing needs and environmental conservation.

Mining roads are one of the most important facilities that greatly affect the smoothness of production and affect mining costs. Therefore, the construction of mining roads must be carried out carefully to meet technical and work safety standards. Road conditions, distance, road slope and road carrying capacity will greatly affect the production capacity of heavy equipment, especially the production capacity of transport equipment. The location of this research is at PT. Energi Cahaya Industritama, precisely in Palaran sub-district, Samarinda city, East Kalimantan province. After observations were made at the research location, it was found that the geometric conditions of the road did not comply with the standards based on the overburden transport equipment or the largest transport equipment, for example, the width of the road on bends and the slope of the road. After conducting the research, the results of the data from the geometry of the access road were obtained, namely, the actual condition of the geometry of the access road on the straight road width is divided into 6 segments with a width of 13.3 meters, 14.3 meters, 14.5 meters, 13.2 meters, 15 meters, 15.7 meters. Meanwhile, the width of the bend road is also divided into 2 segments with a width of 15.9 meters and 15.5 meters respectively. And on the slope of the road there are 2 segments with values ​​of 11.1% and 14.8% respectively. Based on the results of the simulation software, the productivity of the transport equipment was obtained at 92.42 BCM/hour, which shows that productivity has increased by 12.23 BCM/hour from the actual productivity value of 80.109 BCM/hour. It has an average cycle time of 10.33 minutes, which shows a reduction in time or 6.01 minutes faster than the actual average cycle time of 16.34 minutes.

This study aims to analyze the development and trends in rice production in North Sumatra Province during the period 2020–2024 using a descriptive statistical approach. The data used is secondary data from the Central Statistics Agency (BPS) in the form of rice production, harvest area, and productivity. The results of the analysis show that rice production fluctuated but tended to increase, with the highest production in 2024 at 2,204,875.51 tons and the lowest in 2021 at 2,004,142.51 tons. Trend analysis produced a positive slope value of 32,861 tons per year, indicating a long-term upward trend in production. The correlation between harvest area and production shows a strong positive relationship, where an increase in harvest area is consistently followed by an increase in production. Factors affecting production fluctuations include climate change, land area, cropping patterns, and agricultural infrastructure and policy support. Overall, the results of the study confirm that increases in rice production are highly dependent on land management, productivity, and the stability of climatic conditions in the North Sumatra region.

Exotic Dramatic fashion, this fashion reflects a person's gentle personality, as well as a firm and strong side in some situations. Exotic dramatic clothing can be worn on formal or non-formal occasions. The problem that will be discussed is how the process of making exotic dramatic clothing with slope batik, santung and synthetic leather webbing. While the benefits can be to know the manufacture of exotic dramatic clothing with slope batik, santung and synthetic leather webbing. The method used by the author is the R&D method. This exotic dramatic fashion has 3 parts of fashion which include, crop top, dress, custom skirt, with standard size M, making archetypes, breaking patterns, making wicker, preparing tools and materials, sewing. The clothes on the Crop top three-axis wicker technique are located on the front of the bottom and on the back, the combination of slope batik motifs whose patterns are regular slashes and the combination of red and black materials makes an exotic impression. Making this fashion with slope batik, santung and synthetic leather webbing, in making woven size 3 cm wide 65 cm long which is sewn once so that the finished woven product becomes neat and not wavy. In the hollow three-axis webbing, it should be helped by sewing hands outside as a woven barrier on clothes so that they are not easily shifted and the result is neater.