2031 research outputs found
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Development of a Framework for Risk-Based Integrated Safety Audit to Enhance Construction Safety Performance
Get PDFPresently, there is a notable surge in infrastructure development, leading to a heightened occurrence of accidents within the construction sector. This trend has positioned the construction industry as one of the most accident-prone areas compared to other sectors. This suggests that the current construction safety audit procedures have not proven effective in preventing accidents. Typically, audits are conducted primarily during the construction phase, with infrequent assessments during the design phase. According to the Szymberski theory, actions taken during the design phase significantly influence the occurrence of accidents more than those taken during construction. Previous research has discussed a lot about safety management systems. However, it has not discussed how to assure the quality of its implementation. Considering this, the research aims to (a) identify the processes, elements, activities, sub-elements, objectives, criteria, and risks associated with construction safety audits and (b) formulate an integrated, risk-based audit process covering both the design and construction phases. This qualitative research employed the Delphi method to gather insights from construction safety experts, and the developed audit process utilized a risk management approach. The resulting audit process integrates principles from ISO 19011:2018 and Regulation of the Minister of Public Works and Housing Number 10 of 2021. The findings revealed 34 activities in audit program management, 34 activities in audit implementation, and 32 sub-elements in audit criteria. These components are incorporated into a comprehensive construction safety audit framework, organizing audit processes, activities, and criteria. This framework underscores that improving construction safety performance is not solely confined to the construction phase but extends to the design phase as well. The audit results serve as a foundation for continuous improvement, aiding in enhancing safety performance and preventing accidents within the construction industry. Doi: 10.28991/CEJ-2024-010-03-08 Full Text: PD
Silica Quartz Characteristics from Local Silica Sand on Compressive Strength of Mortar
Get PDFMany minerals, including quartz sand, granite, and feldspar, contain silica (SiO2), a substance that performs the same function as quartz. Silicate (SiO2), the primary mineral found in silica sand, can be added to concrete mixtures to boost strength. This means that silica sand can be employed as a cementitious component in concrete because it is believed to have pozzolanic and amorphous qualities. This study is part of a series that tries to use silica sand from an area in Indonesia. The purpose of this research was to manufacture and describe quartz silica (QS) from Kolaka silica sand, which was acquired from Southeast Sulawesi province in eastern Indonesia. In order to improve the characteristics of mortar mixtures that use composite Portland cement as a binder, it is advised to combine the X-ray diffraction process with an evaluation of the impact of addition (QS) on their physical and mechanical properties (volume weight and compressive strength). Laboratory experimentation is being conducted here. Water, cement, and silica sand are used to make mortar specimens. Red and white silica sand is the type of silica utilized. The specimens were created with a 50 mm diameter and a 100 mm height. Tests on mortar's compressive strength were performed after 7, 14, and 28 days. The study's findings indicated that the amounts of quartz formed in red and white silica sand were 45.05% and 91.87%, respectively. The volume weight that results is approximately 2.78 gr/cm3. Red silica sand was tested for compressive strength at ages 7, 14, and 28 days, and the findings were 20.73, 23.32, and 24.61 MPa, respectively. White silica sand has compressive strengths of 21.83, 24.67, and 26.52 MPa. We are aware of no prior studies examining the use of crystalline silica from Kolaka silica sand to enhance the mechanical qualities of cement mortar. Doi: 10.28991/CEJ-2024-010-08-010 Full Text: PD
Evaluating Recycled PET as an Alternative Material for the Construction Sector Towards Sustainability
Get PDFAddressing the environmental threat of Polyethylene Terephthalate (PET) waste is critical for sustainable development. Despite PET's prevalence in everyday products, its improper disposal endangers environmental health. This study targets a pivotal gap in current research. PET waste's potential as a sustainable building material will be thoroughly evaluated, focusing on whether recycling PET waste is feasible. In the construction industry, it can be a substitute for natural sand and an additive in cement. This study contributes to a dual-purpose solution: mitigating environmental pollution and innovating in construction material science. The systematic literature review (SLR) delves into existing studies, focusing on PET's impact on concrete properties when substituting natural sand at ratios of 5% to 20% and as a cement additive at 0.5% to 2% by weight. The findings revealed that up to a 10% PET replacement enhances compressive strength, highlighting a sustainable pathway for construction practices. However, replacements above 10% show a reduction in strength, indicating an optimal substitution threshold. Moreover, incorporating PET additives at 1% by cement weight optimizes flexural strength, underscoring the material's viability in enhancing structural integrity. This study sheds light on PET waste's application in reducing environmental impact and proposes a viable, eco-friendly alternative for construction materials. The recommendation for further research underscores the necessity to refine PET's application in construction, aiming to bridge the knowledge gap and encourage sustainable future innovations. Doi: 10.28991/CEJ-2024-010-04-020 Full Text: PD
The Effectiveness of Inclined Pile Breakwater on the Transmission Coefficient
Get PDFA breakwater is a structure designed to protect coastal areas by breaking and reducing the force of incoming waves. Waves that propagate through a wave dampening building will have some of their energy reflected (reflection), some of their energy transmitted (transmission), and some of their energy destroyed (dissipation). The effectiveness of wave-breaking structures in protecting coastal and harbor waters can be seen from how much wave energy the building can reduce. In this research, the performance of the wave breaker will be seen from the values of wave transmission (Kt) and wave reflection (Kr) with an inclined pile building structure. Reflection and transmission analysis of the results of 2D physical model testing of wave breakers with inclined pile structures are needed to optimize their use. Laboratory test results prove that this Inclined Pile Structure breakwater is quite effective in scenarios that have smaller Kt values and larger Kr values. In this experiment, testing was carried out with several parameters, namely the slope of the pile, the distance between the piles in one row (or distance between pillars), the distance between the tops of the piles (or distance between rows of piles), and the depth of the water. The Kt value in the model α=45°; D=1.69 cm; b=5 cm is 0.603 compared to the model α=60°; D=1.69cm; b=5 cm, Kt value is 0.652. This shows that the inclined pile structure of breakwater is more effective with a pile slope of 45° than with a pile slope of 60°. Doi: 10.28991/CEJ-2024-010-06-09 Full Text: PD
The Effect of Oil Contaminated on Collapse Pattern in Gypseous Soil Using Particle Image Velocimetry and Simulation
Get PDFGypseous soil covers approximately 30% of Iraqi lands and is widely used in geotechnical and construction engineering as it is. The demand for residential complexes has increased, so one of the significant challenges in studying gypsum soil due to its unique behavior is understanding its interaction with foundations, such as strip and square footing. This is because there is a lack of experiments that provide total displacement diagrams or failure envelopes, which are well-considered for non-problematic soil. The aim is to address a comprehensive understanding of the micromechanical properties of dry, saturated, and treated gypseous sandy soils and to analyze the interaction of strip base with this type of soil using particle image velocimetry (PIV) measurement and Plaxis 3D simulation. The results showed that high-resolution digital cameras captured soil deformation using PIV, displacement fields, and velocity vectors were generated, which helped identify different sand movement zones. Further, PIV showed punching and general shear failure in uncontaminated and soaked contaminated gypsum soils, respectively. Moreover, the Plaxis results corresponded well with the PIV, as material behavior models are essentially simplified representations of the actual behavior of footing and soil. Understanding soil deformation behavior is crucial for accurate engineering calculations and designs, making these findings valuable for geotechnical and construction engineering applications. Doi: 10.28991/CEJ-2024-010-07-016 Full Text: PD
Pulsed-Bed Column Adsorption for Triclosan Removal Using Macadamia Nut Shell Activated Carbon
Get PDFTriclosan (TCS), a common antibacterial agent found in numerous personal care products, has been detected in wastewater and surface water and is now of significant environmental concern due to its health impacts. To mitigate this issue, various treatment methods have been explored. This study investigated the efficacy of Macadamia nut shell activated carbon (MAC) as an economical adsorbent for triclosan removal. A pulsed-bed column adsorption technique was applied to enhance adsorption capacity and prolong the operational lifespan of the column. Batch experiments were conducted to explore various parameters and adsorption capacity. Column experiments were carried out to investigate breakthrough curves and various associated parameters. In batch experiments, MAC exhibited a high TCS adsorption capacity of 119.05 mg/g, and optimal adsorption conditions were determined. Adsorption kinetics followed the pseudo-second-order model, and equilibrium data were well-fitted by both the Langmuir and Freundlich isotherm models. A pulsed-bed column adsorption showed superior performance compared to a fixed-bed column under specific conditions (flow rate: 10 mL/min, TCS initial concentration: 60 mg/L, bed column height: 10 cm) and removal bed height of only 6 cm, successfully enhancing TCS adsorption capacity to 53.40 mg/g and extending the operational lifespan of the column to 5,280 minutes. Adapting pulsed-bed columns for TCS removal from wastewater in the personal care product industry led to the extension of column life with increased adsorption capacity and minimized the use of adsorbents as a practical and environmentally friendly method. Doi: 10.28991/CEJ-2024-010-05-019 Full Text: PD
Intelligent Forecasting of Flooding Intensity Using Machine Learning
Get PDFThis innovative study addresses critical flood prediction needs in Bor County, South Sudan, utilizing machine learning to develop an intelligent forecasting model. The research integrates diverse analytical techniques, including land use analysis and rainfall calculations, with a decade of weather data to understand complex hydrological dynamics. This research employs machine learning classifiers such as Support Vector Machines, Decision Trees, and Neural Networks. Findings reveal promising results, with the Linear SVM classifier achieving 87.5% prediction accuracy for raw data and 100% accuracy for high-velocity flooding events. The Naive Bayes classifier matched this performance, while Artificial Neural Networks showed a slight advantage in runoff estimation. The study's novelty lies in its holistic approach, combining machine learning with advanced visualization tools and geographic information systems. This creates a dynamic, real-time forecasting system bridging sophisticated analysis and practical flood management strategies. Focusing on model interpretability and multi-scale forecasting enhances its value to policymakers and disaster management authorities. This research significantly advances the application of AI to flood prediction and disaster management in offering future studies on humanitarian challenges. By enhancing early warning capabilities, this system substantially reduces flood-related losses and transforms disaster preparedness in vulnerable regions worldwide, potentially saving lives and mitigating economic impacts. Doi: 10.28991/CEJ-2024-010-10-010 Full Text: PD
Evaluating Partial Safety Factors for Shear Strength in Bearing Capacity Calculations for Cohesionless Soils
Get PDFCalculating bearing capacity is critical when designing shallow foundations. Many countries use limit state design (LSD) as the standard method for geotechnical design. The paper aims to develop realistic LSD partial factors for bearing capacity calculations of shallow foundations on cohesionless soils based on full-scale model tests. The experimental setup consisted of a hydraulic jack, concrete footing, sand samples, and pressure cells placed in a cylindrical wall. Fifteen sand samples were tested and classified by gradation and relative density. Settlement curves were plotted for each sample under an increasing load. The measured ultimate bearing stresses were found to be higher than theoretical values calculated using traditional methods. This indicates that the traditional approach is conservative. The suggested safety factor for the internal friction angle in cohesionless soils (γtan(ϕ)= 1.10) is notably lower than the values specified in Eurocode 7 at 1.25 and the Egyptian code of practice at 1.30. The proposed LSD partial factors allow for more economical designs than traditional factors while maintaining safety. The full-scale model-testing approach is novel and provides realistic factors directly applicable to Egyptian codes. The results are satisfactory and reasonable for the geotechnical design of shallow foundations on cohesionless soils. Doi: 10.28991/CEJ-2024-010-07-015 Full Text: PD
Flood Hazard Assessment Due to Changes in Land Use and Cover
Get PDFThis study aimed to investigate the influence of land use changes on the occurrence of flood hazards in the Pondok Karya area, Jakarta, Indonesia. Landsat OLI 8 and 7 from 2002 to 2023 were analyzed with a supervised classification tool using Envi and ArcGIS to investigate land use changes over the period. Additionally, the HEC-HMS and HEC-RAS tools were utilized for hydrological and hydraulic assessments under 25 discharge return periods (Q25), using a daily rainfall dataset from 2004 to 2021. The flood hazard index was produced using statistical and GIS methodologies and was based on Neighbourhood Associations (NAs) after qualified hydraulic model performance, indicating a Nash 0.65–Nash-Sutcliffe model efficiency (NSE) value. The analysis revealed considerable alterations in land use and cover within the Pondok Karya watershed. Consequently, the percentage of urban areas surged 30%, whereas vegetative cover declined 24%. Additionally, bare land decreased 9%, and water bodies marginally increased 3%. This indicates a 10% increase in the peak flood river flow of Mampang, from approximately 90 m³/s to 100 m³/s within this period. Subsequently, the percentage of high-risk areas increased from 42.85% (six NAs) to 57.14% (eight NAs), whereas the percentage of low-risk areas decreased from 14.29% (two NAs) to 7.14% (one NAs). Moderate-risk areas also decreased from 42.85% (six NAs) to 35.71% (five NAs). The study found that despite vegetative cover exceeding 30%, the capacity of the Mampang River remained inadequate, and the risk of flooding increased with the impact of its conversion. Additionally, the soil properties and social intervention factors contributed to the performance of the inundation model. Our study underscores the need for further research to mitigate flood risks and advocate interventions such as reservoir construction or river normalization in the upper Mampang catchment area. This study is useful for both local and central governments, which act as decision-makers to reduce the risk of flooding. Doi: 10.28991/CEJ-2024-010-12-04 Full Text: PD
Seismic Isolators Layout Optimization Using Genetic Algorithm Within the Pymoo Framework
Get PDFIn most previous studies, seismic base isolation system optimization has mainly focused on determining isolation layer parameters. However, the subsequent steps of isolator device selection and positioning can significantly impact overall system performance. To address these shortcomings, we propose an alternative optimization approach demonstrated through two models: regular and irregular 8-storey reinforced concrete structures. This approach utilizes the Pymoo framework and commercially available isolators to find optimal isolator layout configurations in two steps. First, using the equivalent lateral force (ELF) procedure, an initial population of seismic isolators meeting shear strain, base shear coefficient, and buckling requirements was randomly selected from suppliers' elastomeric bearing catalogs. Second, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was used to improve the seismic response of the models under the fast nonlinear analysis (FNA) method by minimizing peak roof acceleration, inter-story drift ratio, displacement of the isolated base layer, as well as maximizing the fundamental period. The results underscore the effectiveness of this approach in improving seismic response. Compared to fixed-base structures, the optimal solutions achieved more than double the fundamental period, reduced peak roof acceleration by over 70%, and diminished base shear force by approximately 50%. This methodology can serve as a reference for future research across various structure types, including hybrid isolation systems and steel structures. Doi: 10.28991/CEJ-2024-010-08-07 Full Text: PD