Journal of Civil Engineering Researchers

Sustainable Neighborhood Waste Management: Hybrid Digestion Approaches for Organic Waste Processing

Seyed Mohammad Hosseini, Zahra Gholami , Meysam Seyfi Kafshgari — Sun, 01 Sep 2024 00:00:00 +0330

Effective waste management is crucial for urban sustainability and environmental conservation. This study evaluates the efficiency and quality of compost produced through normal and thermophilic in-vessel composting and anaerobic digestion within a neighborhood waste management model. By analyzing physicochemical properties, process temperatures, carbon to nitrogen ratios, germination index, and biogas production rates, the study highlights the advantages of integrating these methods. Results indicate that thermophilic in-vessel composting accelerates the composting process, achieving rapid temperature increases and enhanced microbial activity. Anaerobic digestion complements this by producing biogas and yielding high-quality compost with low phytotoxicity. The combined approach not only optimizes compost production and quality but also contributes to renewable energy generation and reduced greenhouse gas emissions. These findings provide a framework for implementing sustainable, localized waste management systems, offering significant insights for policy and operational decisions in municipal waste management.

Analyzing the Nonlinear Dynamics of the Three Degree of Freedom Frame Structure Based on the NewMark-β Method and the Effect of Stiffness on the Displacement of the Structure

Hosein Sarkoyeh, Mohammad Ali Hajarizadeh, Saeed Alaie — Sun, 01 Sep 2024 00:00:00 +0330

The analytical method of the simplified model of a structure has provided a basis for the analysis under the effect of earthquake (dynamic) load, which has an important importance in the seismic analysis of the structure. In this article, three degree of freedom steel frame structure is simulated and analyzed in MATLAB based on the NewMark-β method, taking into account the effect of harmonic loads. The vibration response of the steel frame structure has been analyzed considering the stiffness. The results show that the NewMark-β method is a new idea for earthquake response. The construction of the steel frame according to the range of changes of its elastic modulus through dynamic analysis makes the seismic analysis of the frame structures more practical, as well as the analysis of the SS model, which provides a basis for the size of the stiffness coefficient. By applying force on the top and bottom floors, different structural responses are observed according to the stiffness of the structure. The structure of the SS frame and the effect of the force on it when the force is applied to its floors, according to the height of the floors and the position of applying the force with the change of time, the binding stiffness of the amount of displacement will also change and the stability of the structure will be greatly reduced.

Shallow Foundations and Deep Foundations; Drilled Piers, Aggregate Piers and Stone Columns; Design Recommendations, Construction Considerations, and Performance

Hossein Alimohammadi — Sun, 01 Sep 2024 00:00:00 +0330

This paper presents a comprehensive review of shallow foundations, floor slabs, and deep foundations, focusing on drilled piers, micropiles, aggregate piers, and stone columns. The study aims to consolidate definitions, design methodologies, and construction recommendations pertinent to these foundation types. Shallow foundations, including mat and spread footings, and floor slabs are reviewed with respect to their design considerations and construction techniques, emphasizing their role in efficiently supporting superstructures. Deep foundations such as drilled piers and micropiles are evaluated for their capacity to transfer loads to deeper, more stable layers of soil. The review includes discussions on their design principles, installation methods, and performance in different geotechnical contexts. Additionally, aggregate piers and stone columns are explored as ground improvement techniques, offering insights into their design parameters and construction practices to enhance soil-bearing capacity and mitigate settlement issues. By synthesizing current literature and engineering practices, this review aims to provide engineers, researchers, and practitioners with a comprehensive resource for understanding the complexities of foundation design and construction. Key recommendations are offered to guide future research and practical applications in the field of geotechnical engineering.

Examination of the Value of Domestic Component Levels and the Weight of Company Benefits in High-Rise Building Projects

Talitha Nursyifa Octavia, I Nyoman Dita Pahang Putra — Sun, 01 Sep 2024 00:00:00 +0330

In a construction project, various project management activities assist in achieving project goals in planning, procurement, implementation, and control. In the construction sector, the Ministry of Public Works and Public Housing (PUPR) has mandated that at least 30-85% of products used should be domestic, as measured by the Domestic Component Level (TKDN), and the maximum value for the Company Benefit Weight (BMP) should be 15%. When combined, the TKDN and BMP values should be at least 40%. This regulation aims to reduce product imports and boost the purchase of domestic products, which can significantly improve the national economy if consistently implemented. This study employs a quantitative analysis method using data such as material specifications, material/tool prices, worker wages, Work Unit Price Analysis (AHSP), and Cost Budget Plans (RAB). The calculation shows that the total value for the project is 81.85%, comprising 73.381% for TKDN and 8.43% for BMP. Therefore, it can be confirmed that the construction project of ITS Tower 2 Building in Surabaya complies with the Presidential Regulation of the Republic of Indonesia Number 12 of 2021 mandates meeting the minimum threshold of 40%.

Evaluation of the Impact of Driving Techniques on the Subsoil Stability of Bridge E2 in Manta, Ecuador

Sun, 01 Sep 2024 00:00:00 +0330

This study explored the subsurface dynamics related to pile driving for the foundation of the E2 Bridge in Manta, Ecuador, using advanced geotechnical modeling. The objective was to evaluate the impact of various driving techniques on the mechanical properties of the soil, focusing on the stress distribution and the resulting deformations. The methodology included simulation analysis to compare different driving techniques and adjust them according to the specific soil characteristics at the construction site. The results revealed that by adapting the driving techniques to the local soil conditions, a 25% improvement in subsoil stability was achieved. The conclusions highlight the importance of customizing civil engineering practices according to the geotechnical specificities of each project. The adaptation of driving techniques is proposed as a practical and feasible measure to optimize construction processes, ensuring a more efficient and safer building. Furthermore, the study offers fundamental perspectives for the standardization of driving techniques in different geological contexts, contributing significantly to the improvement of foundation methodologies used in civil engineering.

Experimental Evaluation of the Impact Resistance of Alkali-Activated Slag Concrete under High Temperature

Mohammadhossein Mansourghanaei — Sun, 01 Sep 2024 00:00:00 +0330

In recent years, the use of activated alkaline slag concretes (AASC), has had a wide perspective in civil engineering science due to its many environmental benefits (due to the reduction of the emission of CO₂ gas in the air) and high resistance to impact loads. is in this article, a mixed design of ordinary portland cement concrete (OPCC) containing 500 kg/m³ of portland cement as a control concrete and a mixed design of AASC containing granulated blast furnace slag (GBFS) was made, and the impact resistance of the concrete was tested under the weight-drop impact test (WDIT). It was evaluated at temperatures of 21, 300 and 600 ℃ at the age of 90 days. The obtained results indicate that the increase in temperature has caused a drop in the results of the WDIT, so that in OPCC, the energy absorbed and the flexibility index of concrete samples at a temperature of 600 ℃ drop by 76.92% and it obtained 86.95% improvement compared to 21 ℃ temperature, while in active alkali concrete, these figures brought 66.66 and 14.28% drop in results, respectively. In this regard, the number of impacts required for the occurrence of initial cracks and failure in the concrete sample had a downward trend with increasing temperature. In this experimental research, AASC showed superior results compared to OPCC. The results obtained from the analysis of the images of the scanning electron microscope (SEM) on the concrete samples overlapped with the other tests of this research.