Teknisia

Exploring future inundation risk due to sea level rise using CMIP6 models in Indonesia

Dwi Astuti Wahyu Wulan Pratiwi, Hiromune Yokoki — Sun, 31 May 2026 00:00:00 +0000

Sea level rise (SLR) is one of the most significant impacts of climate change which threatening coastal areas, particularly in archipelagic countries like Indonesia. This study projects the extent of inundation, the number of at-risk populations, and estimates of damage cost due to SLR through 2100. The analysis was conducted by combining the projections of sea level (zos and zostoga) from five CMIP6 models: MIROC6, ACCESS-ESM1-5, CanESM5, NorESM2-MM and MRI-ESM2-0, elevation data from ETOPO2022, tides from TPXO10, and population data from NCAR and IIASA. The estimated damage cost was calculated using a regression model based on historical disaster data from EM-DAT. The findings of the analysis indicate that, without mitigation and adaptation measures, Indonesia could experience permanent inundation of 18,700 to over 39,500 km² with an affected population of around 10 million in 2100. National damage cost due to SLR is projected to reach USD 7 billion in 2050 and increase to USD 10 billion in 2100 in high emission scenario. The provinces with the highest physical impact are South Kalimantan and South Sumatra, highest social impact and damage cost occur in East Java and South Kalimantan. These findings emphasize that climate change mitigation and adaptation policies in Indonesia must be planned equitably and supported by robust projections.

Value engineering using Indonesia’s 2022 National Guideline through decision-making framework for cost optimization in highway infrastructure projects: a case study

Vendie Abma, Citra Dwi Puspita Sari, Tri Nugroho Sulistyantoro, Rizki Budiman — Sun, 31 May 2026 00:00:00 +0000

Infrastructure project often requires a balancing manage between design needs, functional performance, and limited financial resources. It has driven the need for Value Engineering (VE) methods to enhance projects and optimize cost without reducing the quality and performance. This study aims to explore the field implementation of Indonesia’s National Technical Guideline No. 4/P/BM/2022 by the Directorate General of Highways (Bina Marga) on VE within a toll road infrastructure project, using the Solo–Yogyakarta Toll Road (Package 1.2) as a case study. Emphasizing value optimization and cost optimization, the study adopts a mixed-method approach that integrates a Pareto principle-based identification of major cost components, a zero–one decision matrix to assess several common borrow material (CBM) sources, a cost–benefit evaluation, and expert insights from fifteen experienced highway engineers. The findings show that combining the use of both Wedi and Sampang quarries provides the best overall value, offering the optimal balance of haul distance, material quality, operational feasibility, and total project costs. The recommended choice results in a cost saving of IDR 51.16 billion (5.05%) while maintaining the required functional performance. Results of the study confirm that systematically implementing the national VE guideline can effectively guide decision-making, enhance project value, and deliver measurable economic benefits. The evaluative process developed offers a practical and replicable framework for applying VE procedures in infrastructure projects, especially in developing countries that need structured methods for cost optimization.

GIS-Based exposure assessment of primary roads and bridges to flood and landslide hazards in Central Java, Indonesia

Berlian Kushari, Muhammad Isran Ramli, Bambang Bakri, Ardy Arsyad — Sun, 31 May 2026 00:00:00 +0000

The continuity of road transportation services is always threatened by flash flood and landslide in Central Java Province that is always exposed to disaster. This study proposes a province-wide GIS-based assessment to determine the most vulnerable road sections and bridges to these hazards. Road and bridge inventories were overlaid on the official BNPB hazard maps by using ArcGIS, and exposure levels were quantified by the length of the road segments and the number of bridges crossing the low-, medium-, and high-hazard areas. The definition of hazard used in this study is the spatial potential of occurrence, not to be understood as a measure of risk of network vulnerability. The results indicate that flash flood exposure is not limited to lowland corridors, but is also prevalent in upland corridors, and that there are significant exposures along riverine systems. In contrast, landslide exposure is more spatially concentrated along upland corridors associated with steep terrain. There are several corridors that are identified as multi-hazard hotspots, such as Karang Pucung – Wangon, Bumiayu – Salem and Kutoarjo – Bruno – Wonosobo. Overall, this study offers explicit spatial information regarding exposure to hazards of the primary road network, which can serve as a basis for prioritization of mitigation, monitoring, and further connectivity-based hazard vulnerability analysis.

Skid resistance analysis in relation to temperature and surface Conditions: a case study of Kaliurang Road KM 8–9

Desfilia Salsabiilaa , Muhamad Abdul Hadi — Sun, 31 May 2026 00:00:00 +0000

The high number of traffic accidents in Yogyakarta requires a review of road surface conditions, especially in terms of skid resistance which is considered a safety indicator. This study analyzes the effect of surface temperature and road condition on skid resistance value on Kaliurang Road KM 8-9 using British Pendulum Test (BPT) tool. This is based on the viscoelasticity of asphalt, micro and macro texture and the effect of water layers. The results indicate that an increase in temperature decreases skid resistance values, or British Pendulum Number (BPN), in all conditions, with dry values ranging from 90 to 74 and wet conditions ranging from 58 to 43. All test points complied with TRRL standard (>65 BPN) under dry condition while only STA 8+000-8+200 segment complied with minimum limit (>55 BPN) under wet condition. The relationship between surface temperature and skid resistance values was determined using Pearson correlation and simple linear regression analyses. The analysis results indicated a significant negative correlation between temperature and skid resistance values and a decrease in BPN of 0.849 in a dry and 0.950 in a wet condition for each increase of 1 °C in temperature. The results of this study showed that temperature and the presence of water are proven to be significant factors that reduce the skid resistance so that pavement maintenance on Kaliurang Road KM 8-9 is needed to reduce the risk of accidents.

Analysis of earthquake impact on market buildings in North Bengkulu using the soil response and finite element method

Sun, 31 May 2026 00:00:00 +0000

The vulnerability of market buildings in active seismic zones, such as North Bengkulu which is surrounded by the Sumatran subduction zone and active faults presents a critical research challenge due to the lack of integrated soil-structure seismic assessments for commercial infrastructure. The aim of this study is to evaluate the effects of earthquakes on the Purwodadi Market Building through the integration of soil response analysis and structural dynamics. The methods employed involved calculating soil response based on historical earthquake records of the 2007 Bengkulu–Mentawai Earthquake (subduction, Mw 8.4) and the 1952 Ketahun Earthquake (active fault, Mw 6.8), followed by structural modelling using the Finite Element Method (FEM). The main quantitative results show that the local clay layer significantly amplifies ground motion, with a Peak Ground Acceleration (PGA) at the surface of 0.485 g for the subduction earthquake and 0.389 g for the fault earthquake. The amplification factors at the surface are 1.95 and 1.73, respectively. Structural simulations recorded a substantial increase in internal forces; for example, the bending moment in beam B1 increased from 0.82 kNm to 61.01 kNm, and the shear force at the head of the pile cap PC increased from 2.15 kN to 65.12 kN. Nevertheless, all structural components maintained stress ratios below 1.0, confirming that the building meets the safety standards of SNI 1726:2019. It is concluded that the integration of site-specific ground response with FEM-based structural dynamics is crucial for improving seismic resistance assessment. This study recommends the continued application of this combined method for buildings in earthquake-prone areas and the expansion of earthquake data coverage to improve future risk mitigation strategies.

Optimization of concrete material supply chain in construction projects using the artificial satellite search algorithm

Moh Nur Sholeh, Mochamad Agung Wibowo, Shifa Fauziyah — Sun, 31 May 2026 00:00:00 +0000

Efficient management of the concrete supply chain is essential for minimizing project delays, reducing costs, and maintaining construction quality. However, the interdependence among batching plants, transportation fleets, and construction sites introduces nonlinear and dynamic challenges that make scheduling optimization highly complex. This study proposes the Artificial Satellite Search Algorithm (ASSA), a novel metaheuristic inspired by the orbital motion and trajectory control of artificial satellites, to optimize concrete material logistics in construction projects. ASSA models the exploration–exploitation process as a dynamic orbital adjustment, enabling adaptive transitions between global search and local refinement. The optimization aims to minimize total logistics cost and delivery delay while adhering to capacity and time constraints. Comparative experiments conducted using both benchmark datasets and real project conditions show that ASSA outperforms Particle Swarm Optimization (PSO) and Genetic Algorithm (GA), achieving a 10.2% cost reduction and a 14.7% improvement in convergence speed. The results demonstrate that ASSA provides a robust and efficient alternative for optimizing material supply chain scheduling in construction management.