Soil materials and road pavement construction materials are subjected to dynamic and repetitive loading of different intensity from vehicle traffic. To account for the cyclic nature of material loading and its non-linear behavior, the concept of the resilient modulus has been adopted. It is a fundamental property of unbound pavement materials, as it quantifies the stiffness of the material under repeated loading. Its real value depends on the actual material parameters—e.g., maximum dry density, moisture content, compaction method, and the number and magnitude of repeated loads—and on the state of stress of the actual pavement structure. The resilient modulus value is therefore not constant for a given material type but varies over a certain interval depending on the above-mentioned parameters and the actual test conditions. Therefore, the method of determining the resilient modulus must take into account all the above factors. The standard method for resilient modulus determination is the cyclic triaxial test, but the cyclic CBR test procedure is also used. It uses standard California Bearing Ratio (CBR) test equipment, and thus it is a very simple and very economical testing method. In the presented paper, the influence of loading force and number of loading cycles on the deformation characteristic and resilient modulus of the analyzed soil is investigated. A total of 72 soil specimens are tested at two different levels of loading force and six different numbers of loading cycles. The obtained results confirm that the resilience modulus increases with increasing loading force value and with increasing number of loading cycles. For the soil analyzed, the resilient modulus ranges in the interval 31-83 MPa.

Due to rapid urbanization and environmental degradation from construction and demolition waste (CDW), effective management, recycling, and reuse of CDW become a necessity. CDW can be appropriately utilized in the development of alternate masonry units, such as stabilized adobe blocks (SAB). However, challenges concerning production uniformity and consistency in the characteristics of SAB exist and require further investigation. To address these issues, this study aims to develop novel controlled flow-stabilized adobe (FSAB) incorporating CDW. This research involves collecting and processing CDW as a substitute for natural soil in the development of FSAB. An experimental study investigates physical, mechanical, and durability characteristics of FSAB as per Bureau of Indian Standards. CDW-based FSAB satisfied minimum block density, water absorption, and compressive strength requirements, confirming its suitability for Class 5 soil-based blocks. Sustainability analysis indicates the embodied energy and carbon equivalent of FSAB possess significant savings, equivalent to conventional masonry units. Environmental indicators such as embodied energy per unit strength, embodied carbon per unit strength, and structural efficiency highlight the potential of CDW-based FSAB as a sustainable alternative to conventional masonry units. These findings demonstrate pathways for waste valorization and reduced dependence on conventional materials while addressing environmental and structural performance challenges.

Soil stress monitoring is critical for accurate soil state assessment in geotechnical engineering, yet conventional resistance-based stress sensors—typically encapsulated in rigid materials—often generate measured values deviating upward from analytical solution predictions, limiting their practical reliability. To address this key limitation, this study aims to propose a novel fiber Bragg grating (FBG)-based flexible stress sensor that integrates the high precision of FBG technology with the adaptive conformability of flexible sensing platforms. For validation, systematic physical modeling tests were conducted using multiple soil types (clay and sand) under different loading protocols, where the proposed sensor’s performance was comprehensively compared with that of a conventional resistance-based rigid sensor. Key findings reveal that the FBG-based flexible sensor delivers more accurate stress measurements in both clay and sand; notably, during cyclic loading within the elastic range, it reverts to its initial state with minimal hysteresis, outperforming the rigid counterpart in dynamic stability. The novelty of this work lies in the fusion of FBG sensing with flexible encapsulation, which mitigates the overestimation issue of rigid sensors and enables more reliable soil stress monitoring for geotechnical applications.

This study investigates the seismic performance of slit link configurations using wide-flange (WF) sections within eccentrically braced frames (EBFs), addressing the limited application of slit geometries in practical steel construction. The objective is to evaluate the influence of slit shape and width on shear strength, ductility, and energy dissipation, while ensuring damage localization within the link element. Six analytical models were developed, including conventional links (CV and CV-ST) and slit variants (SL-1 to SL-4), and analyzed through nonlinear finite element simulations in ABAQUS under the AISC 341-22 cyclic loading protocol. The analysis focused on stress distribution, hysteretic response, backbone curve stability, and energy dissipation. Results show that conventional links provide higher peak shear strength and energy absorption but transmit stresses into adjacent members, increasing repair complexity. In contrast, slit links confine plastic deformation within the link region, enhancing ductility and repairability at the expense of reduced strength. Among the slit variants, the parabolic slit (SL-4) demonstrated smoother stress redistribution and improved cyclic stability compared to rectangular slits. The novelty of this research lies in embedding slit geometries directly into WF profiles, offering a cost-effective fuse mechanism that bridges theoretical slit damper concepts with real-world EBF applications.

Sustainable development seeks to meet present needs without harming future generations. Rising energy demand from coal-fired power plants increases CO₂ emissions and produces fly ash (FA). The cement industry, responsible for about 7% of global CO₂ emissions, also consumes large amounts of energy. Incorporating FA as a partial or complete substitute for cement in concrete provided both environmental and performance advantages. Hence, this study focused on exploring the potential of FA from Nagan Raya (FANR) as a cementitious material for cement replacement. FANR was analyzed using XRF, XRD, FTIR, SEM, and EDS. It mainly contained SiO₂ (48.04%), Al₂O₃ (27.62%), and Fe₂O₃ (11.78%), meeting ASTM Class F fly ash standards. XRD analysis confirmed the presence of amorphous phases along with quartz and mullite crystals. FTIR showed silicate hydration products (C–S–H and C–A–H gels) at different water–cement ratios. SEM showed spherical particles with rough surfaces, which enhance reactivity but also increase water absorption and reduce workability. EDS confirmed silicate and aluminosilicate compositions. These results highlight FANR’s potential as a sustainable cement replacement, despite workability issues.

This study aims to propose a practical indicator that enables quick and reliable evaluation of the relationship between influent characteristics and energy performance and recovery in municipal wastewater treatment plants (WWTPs). A composite Wastewater Strength Indicator (WWSI) was developed, integrating wastewater dilution and pollutant load into a single metric. Theoretical correlations were established through mathematical estimation and verified using case studies of six WWTPs in Bulgaria based on operational data from 2020–2022. WWSI correlates strongly with both specific energy consumption (kWh/kg COD removed) and electrical energy recovery rate. WWTPs with a WWSI below 0.25 perform unsatisfactory, exhibiting specific energy consumption levels above 2.0 kWh/kg removed COD, whereas those with a WWSI above 0.35 demonstrate higher energy efficiency, with specific consumption below 1.0 kWh/kg removed COD. The treatment of low-strength wastewater leads to inherent energy inefficiencies that are difficult to overcome through sludge digestion and cogeneration alone. Despite sludge calorific values ranging from 11.5 to 19.4 MJ/kg, the energy recovery potential in the studied WWTPs remained below 35%, confirming that energy neutrality is challenging for diluted wastewater. A conversion coefficient of 0.039 kWh/MJ was introduced to facilitate rapid estimation of potential electrical recovery from sludge calorific values. The proposed WWSI provides a simple yet effective tool for benchmarking WWTPs and supports future upgrades toward energy-neutral wastewater management.

The study aims to scientifically substantiate optimal drilling-and-blasting (D&B) parameters for driving underground mine workings under complex geological and mining conditions at the Akzhal deposit. The work addresses the selection of explosive types and the rational depth, configuration, and design of cut boreholes, together with their blasting pattern (BP), to improve rock-mass stability, operational safety, and advance efficiency. The methodology combines an assessment of geological-technical conditions with a review of current blasting practice, mathematical and numerical modelling of blast-induced face breakage, and pilot-scale industrial trials supported by statistical analysis and techno-economic evaluation under routine production constraints and reporting. The results show that optimization of the BP increases the borehole utilization factor (BUF) from η = 0.85 to η = 0.98. The locally produced Granulite A6 is proven effective, reducing blasting costs by 1.5 times relative to AS-8 while preserving the required energy characteristics. Charge optimization improves excavation-contour quality, enhances fragmentation uniformity, and reduces overbreak; the most rational solution is a rhombic cut combined with Granulite A6. Scientific novelty lies in integrating geological-geomechanical analysis, 3D modelling in Micromine, and industrial validation. Practical relevance is confirmed by decreasing cycle costs from USD 538.85 to USD 489.38, improving BUF, and enhancing contour quality.

The substantial amount of rainfall leading to runoff in floodplain regions poses hazards to residents within these areas and surrounding zones; consequently, flood simulation is crucial for precise risk evaluation and the formulation of water utilization strategies. In this research, hydraulic and hydrological models, supported by Geographic Information Systems (GIS), were employed to simulate rainfall-runoff mechanisms in Wasit Governorate, central Iraq. A resolution of 30 m Digital Elevation Model (DEM) was supplied by the USGS, geospatially processed, and then imported into the Hydrologic Modeling System (HEC-HMS) at the Hydrologic Engineering Center. The runoff within the research area was estimated using the SCS-CN approach. In order to find the Curve Numbers (CN), a number of datasets were combined, including those pertaining to land use, land cover (LULC), and soil types. The HEC-HMS system was fed CN values obtained from GIS, which varied between 73.95 and 97.61. During the incident in November 2015, the Hydrologic Engineering Center's River Analysis System (HEC-RAS) was utilized to simulate floods using the runoff data resulting from HEC-HMS. Inundation maps were produced using RAS-Mapper within HEC-RAS, depicting flood depth and velocity through the study area. The flood model underwent calibration through comparison of the simulation results with satellite imagery for November 14, 2015. Using CSI, the hydrological factors Ia, Muskingum K, and X, and impervious % were adjusted using sensitivity analysis to achieve the greatest convergence between the model and satellite image. The result of CSI was 88.56%, (HR) was 96.31%, and (FAR) was 8.33%. The validation has been done for the calibrated parameters, and the results were compared with satellite imagery for April 3, 2019. The high level of concordance allowed for the final inundation map to be approved. The importance of measuring runoff for managing water resources effectively and reducing flood risks is highlighted by this study.

A monopile is a large-diameter steel cylinder partially inserted into seabeds; thus, it is one of the major selections of offshore wind and tower foundations. This study aimed to investigate the effect of monopile diameter, thickness, and ratio of soil embedded depth to height of water on the lateral and vertical displacements of the embedded part of the pile. In the study, the monopile was subjected to a lateral displacement equivalent to 10% of the pile diameter at the pile head in order to examine the lateral and vertical deformations of the embedded length of the pile. The three-dimensional finite element software PLAXIS 3D was used to simulate the study. The soil layer used consisted of one layer of medium-dense sandy soil. The study involved investigating the location along the embedded depths that exhibit zero lateral and vertical displacements; that location was found to depend on the monopile diameter, wall thickness, and ratio of embedded depth to water height. The depth of zero lateral displacement was found to increase as pile rigidity and wall thickness increase. The study shows that increasing the L/H ratio on the embedded depth of zero lateral displacement, LHzero, diminishes with increasing monopile diameter for the same wall thickness. Also, the variation of lateral displacement along pile length demonstrates a constant trend behavior regardless of pile thicknesses and diameters, but the depth of zero lateral displacement, LHzero, was varied. Furthermore, the monopile diameter effect on the vertical displacement shows that as the monopile diameter increases, the depth of zero vertical displacement decreases. Also, as L/H decreased, the depth of zero vertical displacement declined.

This study introduces a sustainable, performance-driven approach to asphalt pavement design by incorporating oil shale-modified bitumen into hot-mix asphalt (HMA) and evaluating four performance grade (PG) binders. The research provides a comprehensive evaluation of mechanical and rheological behaviors across varying thermal and loading conditions. A key innovation lies in the integration of oil shale, which significantly reduces voids in mineral aggregates (VMA), leading to improved aggregate contact and material densification. This microstructural enhancement directly translates into increased dynamic modulus (E*) and shear modulus (G*), reinforcing the mixture’s stiffness and deformation resistance without the need for costly chemical additives. The results demonstrate that oil shale improves the load-bearing capacity of asphalt mixtures, particularly under high-frequency loading where elastic responses are favored. Moreover, the optimized mixtures maintain a favorable balance between rigidity and flexibility, typically prone to compressive deformation, and benefit from oil shale integration through enhanced stress dissipation characteristics. The study offers a novel pathway for valorizing oil shale, a locally abundant, underutilized material, as a functional asphalt modifier. The findings validate its potential to extend pavement service life, optimize stiffness–temperature profiles, and reduce dependency on virgin bitumen. These results position oil shale as a viable, cost-effective, and environmentally advantageous additive for future-proof pavement engineering.