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Coal hauling activities are an important part of mining operation because they affect production continuity, cycle time efficiency, and operational safety. This study aims to analyze the requirements of road support equipment on the coal hauling road from Sector 4 to the new Coal Processing Plant (CPP) at PT. Asmin Bara Bronang, Central Kalimantan. Based on road geometry, traffic density, California Bearing Ratio (CBR), and Unsurfaced Road Condition Index (URCI). The research method used was applied research with a quantitative approach. Primary data ware collected through field measurements consisting of road geometri observations, traffic density observations, Dynamic Cone Penetrometer (DCP) testing to obtain CBR values, and road surface condition assessment using the URCI method. Secondary data were obtained from the company records. The results showed that the hauling road has a total length of 9.1 km with an average width of 16 m, and grade values ranging from -7.68% to 10.52%, which are still below the maximum standard of 12%. Traffic density reached 184 dump trucks/day, for coal hauling and 62 units/day for construction material transportation, indicating high traffic intensity. CBR values ranged from 7% to 100%, showing variations in subgrade bearing capacity. The URCI value ranged from 72,50 to 91.00, indicating fair to good road conditions. Based on the analysis of road conditions and maintenance area requirements, the recommended support equipment for maintaining the hauling road consists of 1 motor grader unit, 1 compactor unit, 1 bulldozer unit, and 1 water truck unit.

The performance of asphalt mixtures is strongly influenced by the composition of their constituent materials, particularly aggregate size and mixing temperature during production. In many tropical and subtropical regions, asphalt pavements frequently experience rutting, reduced stability, and changes in viscoelastic properties due to high environmental temperatures and heavy traffic loads. These conditions can significantly affect pavement durability, making it essential to produce asphalt mixtures that meet established technical standards. This study aims to analyze the effect of variations in aggregate size distribution and mixing temperature on the Marshall characteristics of Asphalt Concrete Wearing Course (AC-WC) mixtures. The research employs the Marshall test method to evaluate the load-bearing capacity and stability of hot asphalt mixtures and to assess their compliance with ASTM/SNI standards. The results indicate that mixtures with standard aggregate gradation achieve stability values of 985 kg at 120°C, 1055 kg at 140°C, and 1107 kg at 160°C. As mixing temperature increases, flow values decrease, while the Marshall Quotient (MQ) increases, indicating improved stiffness. Higher temperatures also enhance compaction, reducing VIM and VMA while increasing VFA. Conversely, non-standard aggregate gradations result in several parameters failing to meet ASTM/SNI requirements, confirming that standard gradation produces superior asphalt performance.

The foundation of turbine machines in industrial buildings must be able to withstand static and dynamic loads caused by operational vibrations. Generally, reinforced concrete block foundations are used due to their good stability. However, under certain conditions such as limited land, decreased soil bearing capacity, and the need for structural rehabilitation, their application becomes less effective. Therefore, this study aims to analyze the use of Micropile foundations as an alternative for turbine machine foundations at Candi Baru Sugar Factory, Sidoarjo.The research method includes literature studies, soil data collection through Cone Penetration Test (CPT), machine technical data analysis, and the design and analysis of Micropile foundations. The analysis covers bearing capacity, settlement, dynamic response, pile cap design, and cost estimation.The results indicate that Micropiles with a diameter of 0.20 m, a length of 2 m, five piles, and a pile cap size of 2 m × 2 m × 4.5 m are able to safely and stably support the machine load. In addition, this system is considered more efficient in terms of construction time and implementation. Therefore, Micropile foundations are recommended as an effective and economical alternative for turbine machine foundations.

Highways play a strategic role in supporting economic development, so the quality of pavement materials (flexible pavement) must meet previously established quality standards. The Asphalt Concrete Wearing Course (AC-WC) layer, as the topmost layer of flexible pavement, is susceptible to damage caused by aging triggered by environmental conditions, particularly ambient temperature. Temperatures above 30°C are known to accelerate plastic deformation (rutting) and reduce pavement bearing capacity. The Meteorology, Climatology, and Geophysics Agency indicates that temperatures in Lhokseumawe City, North Aceh, range from 33.7–35.3°C with day-night fluctuations that could potentially accelerate the degradation of mechanical properties. This study aims to analyze the Marshall characteristics of AC-WC asphalt mixtures under ambient temperature conditions. The testing was conducted with varying exposure times of 0, 15, 30, 45, 60, 75, and 90 days at a minimum temperature of 23.90°C and a maximum temperature of 31.80°C, with an average humidity of 87.93%. The test results showed that the AC-WC asphalt mixture experienced a decrease in stability value of 21.37% and an increase in flow value of 36.36%, resulting in a decrease in the Marshall Quotient (MQ) value of 42.52%.

The problem faced is the decline in the performance of a 650 liter/minute centrifugal pump due to wear on components, especially the impeller, rolling bearings, and mechanical seals in supplying process water and clean water in industrial production systems. The planning objective is to obtain a maintenance schedule for a 650 liter/minute centrifugal pump for the operational period of 2026 and the ratio between maintenance costs and profits generated by the machine. The maintenance planning method includes collecting maintenance data from previous maintenance periods, reviewing centrifugal pump specifications, applying the inspection, replace, repair, and overhaul (IRRO) approach, estimating the age and price of components that are expected to be damaged, estimating the cost and duration of dismantling and installing components that have been repaired in accordance with the provisions of the requirements for usable components or replacement parts, scheduling maintenance and repairs, estimating maintenance and repair costs for the 2026 period, and determining the ratio of maintenance costs to profits. The planning results are in the form of a maintenance schedule for the 2026 period worth IDR 4,290,000,-, a maintenance cost to profit ratio of 7.44% and the implications indicate that the machine is still suitable for use and prospective for operations in the next few years.  

Expansive clay soil is soil that can expand and contract significantly in response to changes in soil moisture content. This study used an experimental method to stabilize expansive clay soil using a mixture of gypsum waste powder, which was tested using the Atterberg test, the Unconfined Compression Strength test, and the California Bearing Ratio test with mixture variations of 0%, 10%, 20%, and 30%. The results showed that the addition of gypsum waste powder could reduce the expansivity level of the soil from a very high level of 42% to a moderate level of 20%, increase the value in the Unconfined test at a maximum mixture of 10%, and increase the value in the CBR test at a maximum mixture of 30%. Based on the above description, this study aims to determine the extent of the effect of gypsum waste powder on expansive clay soil on the bearing capacity and compressive strength of expansive clay soil.  

Perhitungan daya dukung pondasi yang akurat menjadi aspek penting dalam memastikan stabilitas dan keamanan struktur bangunan secara keseluruhan. Penelitian ini bertujuan untuk membandingkan nilai daya dukung ultimit (Qu) dari pondasi bored pile dengan menggunakan empat pendekatan berbeda, yaitu perhitungan manual menggunakan metode Schmertmann & Nottingham, Mayerhoff (1976), software Allpile, serta hasil uji lapangan dengan PDA (Pile Driving Analyzer). Studi kasus dilakukan pada proyek pembangunan Gedung Fave Hotel yang terletak di Banyumanik, Semarang. Hasil analisis menunjukkan bahwa metode Schmertmann & Nottingham dengan nilai Qu tertinggi sebesar 282,25 ton. Sedangkan nilai terendah berasal dari hasil uji PDA 159,61 ton. Metode Mayerhoff (1976), memberikan nilai sebesar 170,30 ton, sementara Allpile menghasilkan nilai 160,79 ton. Selisih nilai ini disebabkan oleh perbedaan pendekatan dan asumsi yang digunakan oleh masing-masing metode. Secara umum, hasil PDA dianggap paling merepresentasikan kondisi aktual di lapangan karena merupakan hasil uji dinamis langsung pada tiang. Oleh karena itu, pendekatan manual dan software Allpile dapat dijadikan sebagai estimasi awal dalam tahap desain, namun tetap perlu divalidasi melalui pengujian lapangan untuk memperoleh hasil yang lebih realistis dan dapat diandalkan.

The problem with the sugarcane press machine is a decrease in performance in sugarcane pressing because it has been used since 2020 with an initial price of IDR 3,000,000, which is predicted to be IDR 5,500,000 in 2025 which occurs in the main components of the roler mill, V-belt, and bearings. The purpose of scheduling replacements and repairs is to obtain a schedule, estimated maintenance costs, and the ratio of replacement and repair costs to the profit of renting a sugarcane press for the period 2026. The scheduling method includes collecting data on the use of the sugarcane press machine, a list of replacements for 5 components for roler mills, V-belts, bearings, gasoline motor tanks, and engine frames from 34 components, component prices, estimated labor costs, equipment costs, supporting material costs, application of the inspection, replace, repair, and overhaul (IRRO) method, scheduling replacements and repairs, and calculating the ratio of replacement costs to profits. The results of the replacement and repair scheduling are in the form of maintenance costs of IDR 958,000, with a rate of IDR 10,000/hour for 588 hours/year, resulting in a profit of IDR 5,880,000, and a ratio of maintenance and repair costs to profit of 0.16%.

The soil in Kedungdandang Hamlet, Muncar, has previously been identified as expansive clay that is highly sensitive to changes in moisture content and exhibits significant shrink–swell behavior, which leads to a reduction in bearing capacity and structural damage such as cracking in floors and walls, therefore, soil improvement through stabilization is required. This study aims to determine the effect of adding cement and rice husk ash (RHA) on the mechanical properties of expansive clay soil by using 3% cement and 6%, 8%, and 10% rice husk ash based on the weight of the soil. The results of the unconfined compressive strength (UCT) test indicate that the natural soil has a qu value of 28.62 kN/m², which increases to 55.08 kN/m² with the addition of 3% cement and 6% RHA, to 62.66 kN/m² with 3% cement and 8% RHA, and reaches the highest value of 86.98 kN/m² for the mixture containing 3% cement and 10% RHA. This increase in qu value indicates that the stabilization process improves the mechanical properties of the soil through a pozzolanic reaction, resulting in a more stable soil structure and a higher bearing capacity.

The development of transportation infrastructure in Indonesia continues to be prioritized to enhance regional connectivity, including the maintenance and replacement of bridges that have exceeded their service life. The Semut Bridge in Surabaya, originally a three-span reinforced concrete girder bridge, has experienced structural deterioration due to corrosion and the presence of a central pier obstructing river flow. These conditions have reduced hydraulic capacity, increased sedimentation risk, and heightened the potential for flooding. This study redesigns the Semut Bridge by converting the existing structure into a single-span Howe truss steel bridge. The load analysis refers to SNI 1725 using the Load and Resistance Factor Design (LRFD) method, while structural modeling was carried out both manually and with SAP2000 software. The planning includes the vehicle deck slab, composite girders, main truss members, connections, elastomeric bearings, and abutments. The results show that the bridge deck uses a 20 cm thick reinforced concrete slab with a one-way reinforcement system. Composite girders employ WF profiles, connections use shear connector studs with 25 mm diameter, and the main truss members adopt WF 900×300×16×38 profiles. The total concrete volume required is 282.6 m³, and the estimated steel demand reaches 122,383.79 kg. The single-span design eliminates the central pier, thereby improving river flow capacity while providing a structurally efficient, durable, and easily maintained solution.

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.

Mining roads play an important role in supporting the smooth running of mining activities, especially in the process of transporting materials. The bearing capacity of the soil as a road subgrade greatly affects the stability and resistance of the road to heavy equipment loads. This study aims to analyze the effect of the plasticity index and compaction parameters on the California Bearing Ratio (CBR) value, as well as to determine the thickness of the road layer based on the laboratory CBR value. Testing was carried out at the South Pit of PT. Bina Sarana Sukses site PT. Baramulti Suksessarana with a field test method using the Dynamic Cone Penetrometer (DCP) and laboratory tests such as proctor tests, Atterberg limit tests, and CBR tests on various variations of clay and sand soil mixtures. The results showed that increasing the plasticity index decreased the CBR value, while increasing the maximum dry density and decreasing the optimum water content increased the CBR value. Based on the laboratory CBR value, recommendations were obtained for the appropriate road layer thickness to ensure optimal bearing capacity for heavy equipment passing through the research area.

Clay soil stabilization is a crucial process to enhance the soil's bearing capacity and stability, making it more suitable for construction purposes. Stabilizing clay soils improves their mechanical properties, reduces swelling, and increases their load-bearing capacity, which is essential for the foundation of various structures. This study aims to investigate the effect of lime (CaO) addition and curing time on the physical properties of clay soil, particularly focusing on unconfined compressive strength (qu) and overall soil stability. The experimental methodology involved applying different percentages of lime content (ranging from 3% to 7%) and varying curing times (7, 14, and 28 days). The soil samples were tested for their unconfined compressive strength after each combination of lime content and curing duration. The results indicated that the addition of 5% lime (CaO) and curing for 14 days led to a significant improvement in the unconfined compressive strength by 153.3%, compared to the untreated clay soil. Furthermore, increasing the curing time beyond 14 days did not show substantial improvements in strength, suggesting that 14 days is the optimal curing period for this combination. The study also highlighted that the lime treatment not only enhanced the mechanical properties but also reduced the plasticity of the clay, making it more stable and easier to handle during construction. Based on these findings, it can be concluded that the appropriate combination of lime content and curing time plays a significant role in improving the stability of clay soils. This research provides valuable insights into optimizing soil stabilization techniques, offering an effective solution for enhancing soil properties for engineering applications

Settlement of the ground floor of stockpile is caused by ground pressure of coal pile which is bigger than stockpile floor bearing capacity leads to bury under of some coal. So it is needed to do a study of optimum capacity by stockpile floor bearing capacity. Study of stockpile optimum capacity is started by calculating Californian Bearing Ratio (CBR) of stockpile subgrade using dynamic cone penetrometer in some location on each of the stockpile compartment. CBR value of stockpile subgrade converted into bearing ratio, so the maximum tonage of stockpile can be known. By considerating of pile height, angle of repose of  low grade coal, monthly production target, and the road geometry for mechanical equipment access purpose, the optimum capacity of PT Putra Muba Coal stockpile is 198.549,95 ton, which divided into seven coal piles.    

In geotechnical engineering, building robust structures is crucial to ensure the bearing capacity of structures against external forces, so making sure soil strength and unreliable build cost and duration prediction are also very important and preliminary aspects of any construction project. Therefore, in this first-of-its-kind modern examine, the capability of various artificially intelligent (AI)-based models toward reliable forecasting and estimation of preliminary construction expenses, duration, and strength at shear is explored. First, background information about the revolutionary artificial intelligence (AI) technique along with its many distinct models ideal for geotechnical and building engineering problems is presented, The use of AI-based models in the literature for the aforementioned construction and maintenance applications is discussed in a number of current works, together with their benefits, drawbacks, and future directions. Several important input elements that significantly affect the preliminary price of construction, construction time, and soil's shear strength estimation are listed and given through analysis. Finally, some obstacles to employing AI-based models for precise forecasts in these applications are discussed, along with elements influencing the problems with cost overruns. Thus, this work can help civil engineers make effective use of artificial intelligence (AI) to solve difficult and risky tasks. It can also be used to Internet of Things (IoT) environments for self-learning applications like smart architectural health-monitoring systems

This study uses primary data in the form of types of damage identified through direct surveys in the field and the thickness of the existing pavement layer carried out by asphalt test-pit testing. The secondary data obtained from the Makassar City Public Works Agency in the form of road pavement data, LHR 2021-2023, CBR, and deflection data in 2023. The results of the analysis show that the condition of Jalan Hertasning - Jalan Yasin Limpo with the pavement on the section is classified as fair with the highest PCI value of 77 in the excellent rating and the lowest of 22 in the very poor rating. The analysis of the new pavement was carried out using the 2017 Bina Marga method, the thickness of the AC-WC layer is 4 cm, AC-BC is 6 cm thick, AC-Base is 8 cm thick, Class A Foundation Layer is 30 cm thick, and Class S additional Foundation Layer is 20 cm thick. Through the mechanistic-empirical method of the KENPAVE program, it shows that the additional pavement layer (overlay) of the Hertasning Street to Yasin Limpo Street section for fatigue cracking damage is 0.0001992 with a load repetition value of 1,441,176 ESAL. The remaining value of the 20-year design life, obtained the thickness of the AC-WC pavement layer of 4 cm, the AC-BC layer of 6 cm, the AC-Base layer of 8 cm, and for the Class A upper foundation layer of 30 cm and an additional layer with Class S aggregate of 20 cm thick which is placed under the Class A Foundation Layer. Meanwhile, based on the KENPAVE program, it shows that during the 20-year design life, the pavement can withstand the load without damage because the load repetition control value is greater than the planned LHR value (Nr). The remaining design life value on Jalan Hertasning to Jalan Yasin Limpo using the Bina Marga 2017 method shows that the planned thickness of the new pavement layer is given an additional layer because the soil bearing capacity is less than 6% so that it is necessary to provide embankment material as a form of soil improvement for the minimum road foundation design in Bina Marga 2017.    

Clay soils generally have low bearing capacity and are vulnerable to the water. Therfore, stabilization is necessary as an effort to increase the bearing capacity and improve the other parameters, one fo them by adding other materials such as fly ash and coral limestone powder as done in this research. The purpose of this research is to understand the effect of fly ash and coral limestone powder addition to the bearing capacity of clay soils after compaction process in term of CBR value by adding 15% fly ash and 0%, 10%, 20%, 30% coral limestone powder variations. The analysis results show that the original soil is an inorganic clay with 47,84% plasticity index. By adding fly ash and coral limestone powder variations decreases the plasticity index value to the lowest value 20,23%. The specific gravity increased on the 15% fly ash addition from 2,63 to 2,868 and decreased along with coral limestone powder addition to the lowest value 2,556. The maximum dry density decreased by adding 15% fly ash from 1,465 gr/cm3 on the original soil to 1,450 gr/cm3 and increased along with coral limestone powder addition to the highest value 1,522 gr/cm3. The optimum moisture content decreased along with the fly ash and coral limestone powder addition from 26,80% to 20,50%. The CBR value increased from the lowest value 0,47% to the highest value 15,29%.

This research addresses the issue of corporate criminal liability in crimes occurring within Indonesia’s oil and gas sector. In modern criminal law, corporations are increasingly recognized as legal entities capable of bearing criminal responsibility, particularly in cases related to economic offenses, environmental violations, and corruption. The oil and gas sector, being one of the most strategic and high-value industries, is highly susceptible to legal violations by corporate entities. Given the significant role this sector plays in the national economy, the accountability of corporations in this field is of utmost importance to ensure proper legal oversight and prevent harmful practices. The research employs a normative juridical approach, utilizing statutory, conceptual, and case study methods to examine how corporate criminal liability is applied in the oil and gas industry in Indonesia. The findings reveal that the regulation of corporate criminal liability in the oil and gas sector remains underdeveloped, as it is not explicitly addressed in the Oil and Gas Law. This lack of clear and specific regulation creates gaps in law enforcement, leaving corporations with opportunities to evade full accountability for crimes they commit. While existing legal frameworks such as the Anti-Corruption Law, Environmental Law, and PERMA No. 13/2016 provide a foundation for criminalizing corporations in cases of wrongdoing, the practical implementation of these regulations within the oil and gas sector has proven to be insufficient. Several factors contribute to the weak enforcement of corporate criminal liability. First, there are technical challenges in proving corporate involvement in criminal acts, as the actions of a corporation are often difficult to attribute to specific individuals. Second, the capacity of law enforcement agencies to effectively investigate and prosecute corporate crimes is limited, compounded by a lack of expertise and resources.

The bearing capacity of the soil is the support of the foundation, where the foundation transmits the loads derived from the weight of the building itself and the loads acting on the building to the surrounding soil. The purpose of this paper is to determine the handling of seepage and soil reinforcement needed in the case study of the Margatiga Dam Project, East Lampung. Based on the results of geological investigations, the Margatiga Dam is composed of a quarter-aged rock layer with a fragment composition of fine sand - gravel, with a soft - hard hardness level and the need for foundation repair. Based on the lithological conditions of the Margatiga Dam Extraction Gate foundation and the Spillway building which are composed of relatively deep and quite porous alluvial sand deposits, this causes the curtain grouting results to be ineffective, therefore it is necessary to change the seepage control design from the Grouting Curtain to the boundary wall. Based on the simulation check in Plaxis Software for Seepage and Excavation Staging, processing was carried out using Secant Pile and Soldier Pile with a depth of 30 meters with a stretch of 140 m and overlapping with Curtain Grouting of Embankment Dam on the left side and 5 m right side. Field PMT results showed that the maximum stress of the rock layer under the spillway foundation was 0.016 MPa and 0.630 MPa.    

Technological development is urgently needed to handle rice drying, namely by designing and designing rice drying machines, by utilizing heating from burning LPG gas which is arranged in an integrated system. The purpose of this paper is to design and design a rice drying machine, selecting machine components and including analysis of the strength of the dryer shaft by knowing von Misses stress, displacement and safety factors.  The design of the rice drying machine uses 1 source of electric motor driving power to operate an integrated drying and heating system. With the power of 0.5 HP (0.37 kW) it is planned to be able to dry rice with a capacity of 30 kg/hour. The power generated by the electric motor is used to move pulley-1 (drive), which is transmitted using  V-belt transmission to move pulley-2 (gear box and dryer blower). The length of the first belt transmission (L) is 813 mm and the second is 1270 mm. And uses a chain transmission with type number 40 which has a distance of 12.70 mm with a chain length of 76 links. The bearing used is a radial ball bearing with a single row UCP 205. Based on the results of the analysis of the rice drying machine shaft using solidwork software, Von Misses stress value is 40.55 MPa, displacement value is 0.19 mm, and safety factor value is 13.07, so from the simulation results this rice drying shaft can be said to be safe in accepting workloads