GEOMATE Journal

EFFECT OF TWIN TUNNEL GEOMETRY ON LINING PERFORMANCE AND GROUND SETTLEMENT: A CASE STUDY

Thai Do Ngoc — 2025-10-13

The increasing need for urbanization has led to the construction of numerous tunnels in urban areas to meet growing transportation demands. A distinctive feature of urban traffic tunnels is the construction of two parallel tunnels located in close proximity to one another. Investigating the mechanical interaction between these twin tunnels during the design phase is crucial. This study employs the finite element method to investigate the mechanical interaction between twin tunnels, extending the study of the deflection angles between the two tunnels at the B-B section of Metro Line No. 1 in Ho Chi Minh City, Vietnam. The key findings are as follows: The normal forces in the lining of the upper tunnel reach their maximum when the offset tunnel configuration has an angular relative position of α = 30°. For piggyback tunnel geometries, increasing depth results in the highest magnitude of normal forces in the lining of the lower tunnel. Due to tunnel interaction, the maximum bending moments in both the upper and lower tunnel linings occur in the offset tunnel configuration with α = 45°. The maximum ground surface settlement caused by twin tunnel construction is greater than that of a single tunnel in greenfield conditions. The side-by-side tunnel configuration results in the smallest ground settlement, while the offset arrangement with α = 60° results in the largest ground settlement. These findings provide valuable insights for the design and construction of twin tunnels in urban environments, emphasizing the importance of understanding tunnel interaction under different configurations.

BOND STRENGTH OF BANANA STEM FIBER REINFORCED CONCRETE UNDER NON-STANDARD CURING

Mielke Rievoulda Irianne Alfrits Josef Mondoringin — 2025-10-13

Today, worries about the problems and impacts of environmental damage have become a reality, so the use and development of novel, environmentally friendly materials is a challenge. The presence of natural fibers in concrete materials, among others, functioned to improve the mechanical characteristics of concrete materials, retarded cracks in structural components up to certain loading levels, and reduce structural failure due to corrosion of reinforcing steel. The influences of the percentage of banana stem fiber and variation in bar diameters on the bond strength and other mechanical properties in non-standard curing conditions need to be investigated. This research presented a study of the use of banana stem fiber obtained from the waste of the banana pseudo stem, which is available in large quantities in Indonesia. This experiment method uses a push-off test on the cylindrical specimen. Results show that the larger the plain reinforcement diameter, the smaller the development of bond strength, so the bond strength of banana stem fiber reinforced concrete, called NBSFRC, is inversely proportional to the diameter of the plain reinforcement. The development of bond strength increased significantly at the early ages of the specimen for plain reinforcing bar diameters of 10 mm and 12 mm. Another aspect that may strongly affect the bond strength is the curing process that is not maximal, because after casting, the specimen cannot be immersed in the tub as other test specimens for curing to avoid fast corrosion, but only be wrapped in gunny sacks and watered daily.

FLEXURAL CAPACITY OF COMPOSITE GIRDERS ACCOUNTING FOR BRIDGE HIGH PERFORMANCE STEEL

Dang Viet Duc — 2025-10-13

Elasto-plastic finite element analyses are used in a parametric study to investigate the positive flexural capacity of composite steel girders. The flexural capacity of steel-concrete composite girders using high-performance bridge steel (SBHS) is investigated with regard to web slenderness limits. Furthermore, an investigation is conducted regarding the impact of the initial (early) bending moment resulting from the unshored (unsupported) construction approach on the limits regarding web slenderness for the section classification. The findings from the composite girder's FE simulation model show that the flexural capacity of the composite bridge girders resisting a positive bending moment distribution, predicted by currently designed codes, is particularly conservative. The potential compact-noncompact limit is greater than that of AASHTO and Eurocode by around 50 and 70%, respectively. Many sections show acceptable flexural capacity as noncompact while being categorized as slender by current criteria.

SEISMIC PERFORMANCE OF MASONRY PARTIALLY INFILLED RC FRAME BASED ON NUMERICAL ANALYSIS APPLYING STRUT MODEL

Maidiawati — 2025-10-13

This paper presents the results of a numerical study on reinforced concrete (RC) frame structures with partial masonry infill, conducted using the pushover method in the SeismoStruct program to evaluate their seismic performance. Various diagonal strut models were employed to analyze the strut width and the contact length between the column and infill, which were used in the pushover analysis to represent the masonry infill element. The study investigated three RC frame models: one with full masonry infill and two with partial masonry infills. The numerical results were validated against experimental findings, which showed that the lateral strength, stiffness, and ductility of the structural models were reasonably consistent between the numerical and experimental data. Both sets of results indicated that the lateral strength of the RC frame with full masonry infill decreased by approximately 29% and 46% when compared to frames with three-quarter and half-height infills, respectively. Partial masonry infill was also found to alter the crack patterns and failure mechanisms of boundary columns. In RC frames with partial infills, the walled portions of the columns become stiffer, leading to increased cracking and short-column damage. These findings demonstrate that the diagonal strut approach is effective for evaluating the seismic performance of RC frames with partial masonry infill.

REVIEW OF PORT INFRASTRUCTURE RESILIENCE WITH MATHEMATICAL MODELLING AND A BIBLIOMETRIC APPROACH

I Putu Artama Wiguna — 2025-10-13

This study reviews the resilience of port infrastructure using a mathematical modeling approach and bibliometric analysis. With the increasing threats of climate change and natural disasters, enhancing port infrastructure resilience is crucial for maintaining operational continuity. The bibliometric analysis, focusing on the keyword "Port Infrastructure Resilience," identifies trending and novel keywords for future research, including climate change, risk analysis, resilience, and port facilities. Data from the Scopus database (2014-2024) were analyzed using VOSviewer to map key research trends. Findings indicate that improving port infrastructure resilience to climate change and disasters requires a multidimensional approach, such as structural optimization, drainage improvements, and risk mitigation strategies. Current research trends emphasize sustainability and disaster impact reduction through advanced technology. Investing in monitoring technology and cross-sector strategic planning is essential to enhance port resilience. This study highlights the importance of technological innovation and stakeholder collaboration, recommending further exploration of digital technology adoption for optimizing port resilience. Relevant case studies for mathematical modeling, which can serve as references in future analyses, include multidimensional modeling for coastal flood simulations, optimization models for climate change strategies in ports, seismic design optimization based on building resilience, evaluation of solutions for multi-objective problems, and improved water network distribution optimization methods. These case studies illustrate the diverse and comprehensive approaches necessary to address the complex challenges faced by ports in the context of a changing climate.

UTILIZATION OF DREDGED SOIL-EPS MIXTURE AS A LIGHTWEIGHT MODULAR BLOCKS: A STUDY ON THE BEARING CAPACITY

Nurul Marfuah — 2025-10-13

The increasing demand for sustainable and lightweight construction materials has encouraged the exploration of alternative resources such as dredged soil. This study investigates the mechanical performance of Lightweight Modular Blocks (LMB) composed of dredged soil (DS), cement (C), and Expanded Polystyrene (EPS), with a focus on their applicability as subgrade materials. The research examines the effects of varying cement content (3%, 5%, 7%, and 9%), curing periods (7, 14, and 28 days), and EPS inclusion (0.5% and 0.75%) on the California Bearing Ratio (CBR) value under both unsoaked and soaked conditions. Specimen expansions were recorded at the end of the soaking period (96 hours ). The results indicate that increasing cement content and extending the curing period significantly improve CBR values. Furthermore, these two variables exhibit an interdependent relationship, complementing each other in enhancing soil strength. In contrast, the inclusion of EPS reduces CBR values due to the reduced proportion of the soil-cement matrix and the formation of voids. However, increasing the EPS content proves beneficial in reducing specimen expansion and bulk density, achieving a weight reduction of up to 29%. The findings confirm that, with an optimized curing period, all tested compositions meet the minimum subgrade requirement specified by the Indonesian National Standard (SNI). Further analysis for the future development reveals that: 1) The optimal strength gain is observed in the C7%-14 days composition, 2) The inclusion of 0.5% EPS offers the best balance between strength and weight reduction, 3) For greater weight reduction, 0.75% EPS may be used, provided that a minimum of 7% cement and at least 14 days of curing are applied to maintain structural integrity.

EFFECT OF SUPERPLASTICIZER DOSAGE ON WORKABILITY AND 28-DAY STRENGTH OF GGBFS-FA GEOPOLYMER MORTAR IN VIETNAM

Nguyen Phan Anh — 2025-10-13

Using by-products such as ground granulated blast furnace slag (GGBFS) in binder can be a sustainable alternative to ordinary Portland cement, exhibiting rapid setting and workability loss, which can affect practical applications for this material in mortar and concrete. This research evaluates the effects of chemical admixture, which is a water-reducing and superplasticizer agent made from naphthalene formaldehyde sulfonate, at different dosages on the fresh and hardened properties of geopolymer mortar using GGBFS as a mineral admixture and fly ash (FA) as a filler. The results indicate that workability loss becomes evident when chemical admixture is used at 1.0% and 1.5% of binder weight. Despite the initial decrease in workability over time, the mix proportion using 1.0% and 1.5% chemical admixture demonstrates improved compressive strength at 28 days compared with the mix proportion using 0.5% chemical admixture, which can be up to 26.5% with a p-value is 1.8%. The optimal performance was observed at the mix proportion using 1.5% water reducing and superplasticizer, which balanced workability retention and mechanical strength development. The research promotes the use of eco-friendly GGBFS-FA-based geopolymers with assured performance toward the sustainable development of the construction sector in Vietnam.

EVALUATION OF HYDRAULIC CONDUCTIVITY VARIATIONS INDUCED BY SOIL CRACKING UTILIZING A MODIFIED SEEPAGE TESTING APPARATUS

Putu Tantri Kumala Sari — 2025-10-13

Landslides are a common hazard during the rainy season, particularly in hilly regions with hard, well-compacted soil layers. Due to the low seepage capacity of such soils, rainwater infiltrates slowly, leading to increased surface runoff. While this slow infiltration generally enhances slope stability by reducing pore water pressure, the presence of deep surface cracks can trigger landslides by facilitating rapid water seepage into the subsurface. The accelerated infiltration through cracks is governed by variations in the soil’s seepage coefficient, yet research on this phenomenon remains limited. This study investigates the seepage coefficient of cracked soil using a newly developed modified seepage apparatus designed specifically for fractured soils. Experimental results demonstrate that the seepage coefficient in cracked soil ranges from 4.23 × 10⁻⁵ to 1.01 × 10⁻³ cm/s, indicating significantly higher permeability compared to intact soil. Furthermore, the seepage coefficient increases proportionally with crack width and depth, and the presence of sand infill material within soil cracks further modifies seepage behavior, highlighting the critical role of crack dimensions and composition in governing infiltration rates. These findings provide valuable insights into landslide initiation mechanisms, emphasizing how soil fracturing and infill materials exacerbate rainfall-induced slope failures. The study underscores the need to account for crack-induced seepage and infill effects in slope stability assessments, offering a foundation for improved landslide risk mitigation strategies in vulnerable regions.

ENVIRONMENTAL AND COMPRESSIVE STRENGTH EFFECTS OF COAL BOTTOM ASH AS PARTIAL SAND REPLACEMENT IN CONCRETE: A LEACHING ASSESSMENT STUDY

Fauzan — 2025-10-13

One coal waste is coal bottom ash (CBA), which has an environmental impact due to its heavy metal content. This study reveals the dual role of CBA as a partial sand replacement in concrete through leaching ability analysis to assess mechanical performance and environmental safety. The concrete mixture was prepared by placing CBA at 0%, 30%, 40%, 50%, and 60%, and then a compressive strength test was carried out at the periods of 7 and 28 days. Using the Synthetic Precipitation Leaching Procedure and ICP-MS analysis, the leaching behavior was evaluated. The results showed that adding CBA up to 50% increased the 28-day compressive strength by 6.42% compared to the control concrete. In comparison, higher replacement (60%) caused a decrease in strength due to increased porosity and unburned carbon, which prevented hydration. Leaching tests showed that adding CBA reduced the mobility of Cr, Pb, Zn, and Cd in concrete by combining physical encapsulation in the cement matrix and chemical stabilization by forming calcium silicate hydrate (C–S–H) gel. The maximum reduction was observed at 50% CBA: Cr (27.9%), Pb (67.9%), Zn (1.5%), and Cd (10.2%) compared to control concrete. However, using CBA in concrete needs to be controlled because the concentrations of Cr and Pb in some mixtures exceed the USEPA threshold, indicating potential risks for soil and groundwater. This study is beneficial for sustainable construction.

GIS-BASED CONSTRUCTION GROUND LEVEL MANAGEMENT IN URBAN PLANNING: A CASE STUDY IN HANOI, VIETNAM

Ngoc Tu Tong — 2025-10-13

The management of construction ground levels must be carried out synchronously within a unified coordinate system across all sectors to ensure effective implementation and to minimize the risk of flooding across entire regions. In Vietnam, construction ground-level data in urban planning projects are typically managed by various agencies using different formats. This fragmentation causes significant difficulties in updating, adjusting, and sharing data across agencies. This study proposes the application of Geographic Information Systems (GIS) in developing a construction ground-level database in the Hanoi Software Technology Park Urban Area Project in Phuc Loi ward, Long Bien district - an innercity district of Hanoi. The input data were gathered from the officially approved planning drawing files at a scale of 1:500, dated 2013, and stored in *.dwg format of AutoCad software, including: topographic map; current land use map; detail planning map; technical infrastructure system drawing; communication system layout; and power supply system. A synchronous construction ground-level database was developed within the GIS environment, serving both management and decision-making functions. Moreover, this database is proposed to be publicly and transparently shared among inter-sectoral agencies and local communities, ensuring data accuracy and supporting digital transformation in the management of construction ground levels in particular and urban planning management in general. By visualizing and providing construction ground-level elevation, this result also enables identifying low-lying, flood-prone areas, and analyzing the impact of floods on infrastructure, thereby contributing to more effective flood risk reduction.

STUDY OF THE INTERCONNECTION OF PIT LAKES TO FULFILL RAW WATER NEEDS IN UNDERDEVELOPED AREAS IN BANGKA DISTRICT

Yadi Suryadi — 2025-10-13

Pit lakes, known locally as kolong, are formed from abandoned open-pit mining areas that fill naturally with runoff and groundwater. In Bangka Regency, Sumatra, many communities rely heavily on groundwater from bore wells to meet their raw water needs. However, these sources often experience shortages during prolonged dry seasons. This study aims to explore the potential utilization of Kolong Dam 1 Pemali and Kolong Simpur Pemali as alternative raw water sources through an interconnection system to improve water supply reliability in rural areas, particularly in Pemali District. Bias correction of satellite rainfall data was conducted using the quantile mapping method, significantly increasing the accuracy of precipitation data. Water availability was analyzed using the NRECA method, and future water demand was projected over a 20-year period (2024–2044). Two operational scenarios were simulated: the first, using only Kolong Dam 1 Pemali, failed to meet demand during dry seasons, showing a 91.3% reliability rate. The second, with an interconnected system between both kolong, significantly improved performance, achieving a 97.2% reliability rate. The findings demonstrate that interconnecting kolong provides a technically feasible and effective solution to enhance the reliability of water supply systems in Bangka, especially during seasonal fluctuations in water availability.

STUDY OF UNSTEADY TWO-DIMENSIONAL HORIZONTAL SEEPAGE FLOW USING THE FINITE ELEMENT METHOD

The Hung Nguyen — 2025-10-13

The finite element method (FEM) based on the Galerkin approach is an effective technique for modeling groundwater flow and analyzing seepage, particularly in complex and heterogeneous geological environments. It allows for accurate simulation of groundwater levels, seepage velocity, and pore water pressure, supporting reliable predictions essential for water resource and geotechnical engineering. This study applies the Galerkin-based FEM to evaluate groundwater behavior in Kon Tum City, Vietnam. A computational program developed by the authors using the Fortran language was employed to simulate various groundwater extraction scenarios. Using field data, the model assessed the storage capacity, predicted changes in groundwater levels, and calculated seepage velocity under different pumping conditions. The method’s ability to handle complex boundary conditions contributed to the precision of the simulations. The results demonstrate the FEM’s effectiveness in groundwater modeling and its practical applicability in managing water resources and planning sustainable groundwater extraction strategies.

RESEARCH ON STATIC MECHANICAL PROPERTIES AND MICROSTRUCTURE OF COMPOSITE RUBBER CEMENT MORTAR BASED ON ORTHOGONAL EXPERIMENTS

Chunyi WANG — 2025-10-13

An L16 (4×4) orthogonal experiment was conducted to investigate the effect of rubber particle size, rubber content, fly ash content, and silica fume content on the fluidity and mechanical properties of composite rubber mortar, and the corresponding mechanisms were explored. The results indicated that silica fume exhibited the dominant influence on the fluidity of composite rubber mortar, while the rubber content demonstrated the most significant impact on the compressive strength, flexural strength, and flexural-compression ratio of rubber mortar. As the curing age increased, the reinforcing effect of fly ash and silica fume on the compressive and flexural strength of composite rubber mortar became more pronounced, indicating that an appropriate amount of fly ash and silica fume exerted a positive synergistic effect on the mechanical strength of composite rubber mortar. Furthermore, both fly ash and silica fume can improve the weak interfacial transition zone (ITZ) caused by rubber incorporation. This improvement leads to a denser pore structure in the composite rubber mortar. As a result, the enhanced mechanical properties significantly reduce the strength loss induced by rubber. Through orthogonal experimental analysis, the optimal combination A1B1C4D2 was identified, corresponding to a rubber particle size of 150 mesh, rubber content of 5%, fly ash content of 20%, and silica fume content of 5%. This specific formulation demonstrated the most favorable comprehensive performance characteristics for the composite rubberized mortar.

TLS IMPLEMENTATION FOR URBAN ROAD EVALUATION

Ananda Amatory Zahra — 2025-10-13

This study explores the use of Terrestrial Laser Scanning (TLS) technology, specifically the XGRIDS Lixel L2, for urban road evaluation. Traditional methods, such as manual surveys, and newer technologies, like drones, often face challenges in areas with dense vegetation or rough terrain. TLS, which combines LiDAR and SLAM technologies, offers a portable and precise solution for collecting 3D data, making it suitable for complex environments. In this study, both manual and TLS-based surveys were used to evaluate road gradient, width, and pavement condition. The findings confirm that TLS provides high accuracy, achieving 100% for Pavement Condition Index (PCI), 94.15% for road gradient, and 95.86% for road width. Notably, this study identifies ravelling damage, which was previously unreported, and demonstrates that TLS can detect small potholes, reinforcing the high quality of the generated 3D models. While TLS effectively overcomes UAV LiDAR’s limitations in vegetated areas, tree shadows in real-color mode may obscure certain road damages, which can be mitigated by using RGB mode. Despite its higher cost compared to manual methods, TLS offers detailed and reliable road condition assessments, particularly in complex terrains. Future research should focus on optimizing TLS data acquisition, reducing costs, and integrating Machine Learning (ML) to enhance automatic damage detection and classification, further improving road evaluation processes.

ANALYSIS OF KEY TRENDS IN PAVEMENT CRACKING ON ROADS

Ainash Karashina — 2025-10-13

The formation and propagation of cracks in asphalt concrete pavements remain one of the critical challenges affecting the durability and safety of road infrastructure. This study presents the results of field observations conducted across various climatic regions of Kazakhstan to identify the correlation between climatic conditions and the intensity of transverse crack development. The collected data demonstrate that climatic conditions of the region influence the stress-strain behavior of asphalt concrete, promoting the emergence of temperature-induced cracking. Based on the analysis conducted, the study proposes a technological approach to pavement design that emphasizes the consideration of climatic factors in selecting asphalt concrete mixtures, particularly those incorporating polymer-modified bitumen binders. A key parameter recommended for inclusion in design calculations is the coefficient of thermal expansion and thermal conductivity, both of which significantly affect the distribution of thermal stress throughout the pavement system. The proposed approach enhances the crack resistance of road pavements by integrating thermophysical and mechanical characteristics of construction materials under unstable climate conditions. This facilitates the development of adaptive pavement structures capable of withstanding adverse thermal influences, thereby increasing the structural performance and long-term stability of the road network.

DETERMINATION OF DISPOSAL MATERIAL DENSITY IN OPEN-PIT COAL MINE DISPOSAL AREA

Hidayatullah Sidiq — 2025-10-13

This study proposes a method for determining the density of disposal material in open-pit coal mines using undisturbed sampling with a large sampler tube (LST). The disposal materials in the studied area are mostly mixed between sandstone and claystone from the coal overburden and/or interburden material in the coal open pit. The materials belong to the Warukin Formation in the southeast area of Kalimantan Island. Determination of disposal material density has become necessary since it is related to the planning of the material disposal process in the disposal area and the desire to optimize disposal capacity. The material sampling was conducted at several points in the Kusan and Girimulya disposal areas, and each point was taken at various depths. Sampling locations were also selected based on disposal age: less than 3 months (active disposal), approximately 6 months (slightly active disposal), 12 months and more (old disposal), and mining road to disposals. Additionally, the CBR test was conducted at a location near the material sampling point, where the results will be used for comparison with the density values obtained. The undisturbed sampling of disposal material was conducted using a sampler tube made of galvanized iron with a diameter of 13.3 cm. The natural bulk density is determined by following the procedure of ASTM D2937. The results show that the active Kusan disposal area has low-density material because only 10% of samples have a density equal to or greater than the optimum density, while the active Girimulya disposal area has high-density material because 70% of samples have a density equal to or greater than the optimum density. The results of the study also show that natural compaction with the existing dumping procedure can be achieved after a disposal age of approximately six months. Compared to the CBR values along its depth, the density values obtained from this method are in good trend; the proposed method can be used for monitoring the density of disposal material.

ANALYSIS OF THE CAUSES OF DEFORMATION AND FAILURE OF TRACTION-TYPE SLOPES: A CASE STUDY OF SLOPE ON TIANXI HIGHWAY IN GUANGXI, CHINA

Xiu Xue — 2025-10-13

Slope deformation poses a severe challenge to highway construction. To explore the failure mechanism of typical traction-type deformation slopes, this study systematically evaluated the deformation mechanism of the right slope of the K170+080~K170+260 section of the Guangxi Tianlin to Xilin Highway (referred to as Tianxi Highway) based on field survey and monitoring data, combined with the finite element software PLAXIS 2D. The results show that the sliding zone of the slope is buried at a depth of about 16 m, mainly composed of strongly weathered sandstone, with a semi-soil structure and poor permeability. It is easy to soften under rainfall or surface water infiltration conditions, forming a weak structural surface. The earliest deformation of the slope occurred on June 14, 2021, and then it continued to slide slowly. The toe of the slope was destroyed first, and the upper part suffered delayed destruction about 5 months later. The sliding surface was finally connected, showing typical traction-type deformation characteristics. It shows that the landslide starts from the lower part of the slope, and the toe support should be given priority in reinforcement and management. The internal causes of landslides are mainly special landforms and complex rock and soil structures, while the external causes include artificial excavation and heavy rainfall. Among them, although the excavation work caused some disturbance, the unreasonable drainage layout and the long construction period led to a large amount of rainwater infiltration, which became the main triggering factor. Therefore, the focus of governance should be on improving the drainage system to reduce the impact of rainfall infiltration. This study reveals the progressive deformation mechanism of the typical traction slope of Tianxi Highway under the combined effects of complex geology and rainfall-excavation, clarifies the characteristics of the sliding surface and the main causes, and has important reference value for similar slope stability analysis and engineering prevention and control.

CONSTRUCTION AND UNCERTAINTY ANALYSIS OF URBAN CLIMATE MODELS UNDER MULTI-SOURCE DATA FUSION

Shang Ma — 2025-10-13

Urban climate modeling faces significant challenges in accurately representing complex urban environments while maintaining computational efficiency and quantifying prediction uncertainties. Traditional approaches struggle with heterogeneous data integration and fail to provide reliable uncertainty bounds essential for urban planning decisions. This study develops a novel Adaptive Bayesian Hierarchical Multi-source Fusion (ABHMF) framework that systematically integrates satellite remote sensing, ground observations, IoT sensor networks, urban morphology databases, and numerical weather predictions. The framework employs an adaptive fusion algorithm with dynamic weight adjustment based on real-time data quality assessment, coupled with comprehensive uncertainty propagation through Bayesian hierarchical modeling. Validation across multiple urban environments demonstrates superior performance, achieving an RMSE of 0.51°C with only 10 seconds of computation time per day, representing a 180-fold efficiency improvement over traditional WRF-Urban models. The uncertainty quantification reveals measurement uncertainty as the dominant component (32.5%), followed by model structure (28.3%) and parameter uncertainty (24.7%). During extreme heat events exceeding 35°C, the framework maintains robust performance with an RMSE of 0.68°C. Cross-city transferability assessment shows consistent accuracy (average RMSE: 0.72°C) without site-specific recalibration. The proposed methodology significantly advances urban climate modeling capabilities, providing reliable predictions with quantified uncertainties for climate-resilient urban planning and real-time monitoring applications.

CARBON BALANCE ATTRIBUTION AND STORAGE IN KHON KAEN UNIVERSITY, THAILAND

Watchara Pattanawiwattanaporn — 2025-10-13

Effective terrestrial ecosystem management is essential for enhancing carbon sequestration and achieving carbon neutrality. University towns, characterized by dynamic land use and high per capita emissions, pose challenges to ecosystem stability. This study investigates land use and land cover changes (LULCC) at Khon Kaen University, Thailand—a large university city emitting over 88,000 tons of CO₂ equivalents annually—with emissions projected to reach 105,000 tons by 2040 without intervention. Utilizing Sentinel-2 satellite imagery from 2019 to 2023, we applied remote sensing classification and carbon sequestration models to assess land use dynamics and forecast ecosystem carbon stock over 22 years. Five land categories were classified: forest, agriculture, built-up areas, waterbodies, and bare land. Results indicate a slight increase in forest and agricultural areas (4.51% and 0.41%, respectively), contrasted by a 26.98% rise in built-up land. Current green spaces offset only 0.45% of the university’s total emissions. However, approximately 32% of underutilized land presents an opportunity for rehabilitation, potentially increasing sequestration by 1,575.91 tons CO_₂ equivalents annually. The findings support strategic land use planning, emphasizing forest conservation and ecosystem restoration as viable approaches to enhance carbon sinks. When combined with emission reduction initiatives across operational scopes, Khon Kaen University has the potential to meet its carbon neutrality target within the projected timeline.

UTILIZING CEMENT AND FLY ASH FOR ENHANCEMENT IN SOFT IRAQI SOILS

Zainab H. Shaker — 2025-10-13

Problematic soil, especially soft clay, is widespread in the central and southern parts of Iraq, which is described via its low bearing capacity and settlement problems that occur either during or after construction because of low shear strength, high compressibility, and low permeability of this soil. This study aims to investigate the appropriateness of certain local materials to be utilized as stabilizers, like fly ash and cement, which are obtainable in Iraq at a lower cost. This work was carried out on a soil specimen brought from the Gramet Ali location (538 km) south of Baghdad in Al-Basra city. This study consists of three stabilization strategies using cement, fly ash, and their combination, aiming to systematically enhance shear strength and physical properties through rigorous testing protocols (Specific gravity, Consistency limits, Compaction and Unconfined shear strength with curing time (immediately after preparation sample, 7 days & 28 days) that were carried out, it was determined how the soil's dry weight responded to the supplement of various amounts of fly ash and cement (3%, 5%, and 7% for each additive, respectively). Finding out how the soil reacted to adding varying amounts of each additive allowed us to calculate these percentages. The investigation revealed that incorporating fly ash and cement material into the clay soil resulted in a notable enhancement of the clay soil's shear strength and physical properties.