Journal of the Civil Engineering Forum最新文献

{"title":"Airline Choice Decision for Jakarta-Denpasar Route During the Covid-19 Pandemic","authors":"Christoforine Agatha Setiawan, P. F. Belgiawan, D. Dharmowijoyo","doi":"10.22146/jcef.12569","DOIUrl":"https://doi.org/10.22146/jcef.12569","url":null,"abstract":"As one of the most popular destinations in Indonesia, Bali has experienced growth in its domestic passenger arrivals over the last few years. Travel restrictions during COVID-19 have reduced airline passenger numbers on the Jakarta-Denpasar route. The travel restriction has loosened, and the economy is starting to recover in January 2022. However, the number of domestic passengers arriving in Denpasar has not returned to its former state. This research aims to understand the influential factors in the airline decision-making of domestic passengers on the Jakarta-Denpasar route. We started the research with an exploratory study to find the influential factors in which we obtained five attributes. The attributes include airfare, flight schedule, transit number, travel time, and HEPA filter. We conducted a stated choice experiment with five alternatives: Foreign private LCC, Private FSC, Private LCC, Flag LCC, and Flag FSC. The questionnaire was designed with a D-efficient design. We obtained 256 respondents, and there are 2048 observations for the Mixed Multinomial Logit Model estimation. From the estimation, we found that airfare, number of transits, travel time, and HEPA filter are all significant with expected signs. We also found that the flight schedule is not significant. Several socio-demographic variables, such as Gender, Age (except for Flag FSC), and income (also except for Flag FSC), are insignificant in airline choice decisions. We also presented the calculation of elasticity as well as the willingness to pay. Further, we propose that all airlines increase their direct flights for the Jakarta-Denpasar route since respondents prefer less transit. As people are more concerned about public transport’s hygiene, stating that HEPA filters’ availability in airline promotion is also recommended to gain more trust. Finally, our paper offers recommendations for airlines to improve their services and passenger satisfaction after the pandemic recovery period.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141922824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proposal and Evaluation of Vertical Vibration Theory of Air Caster","authors":"Tetsunoshin Ito, M. Nazari, Kazuaki Inaba","doi":"10.22146/jcef.13020","DOIUrl":"https://doi.org/10.22146/jcef.13020","url":null,"abstract":"Urbanization and human development have increased the exposure of seismic risk. Therefore, engineers need to develop new and more efficient technologies to protect people and objects from the disastrous consequences of earthquakes. Air casters have gained attention and have been utilized in the past decade as effective seismic vibration control devices. Although such active isolation systems perform well in mitigating horizontal input vibrations, they might cause excessive rocking motions, if not designed properly. This fact emphasizes the importance of exploring the vertical dynamic properties of air isolation systems. To gain such an understanding, this research examines and proposes a formula for the vertical stiffness and damping of air caster systems. Theoretical solutions to the vertical stiffness and damping of such systems have been explored. Computer simulations considering fluid-structure interaction have also been performed to understand the dynamic behavior of the supporting air layer. Results have been compared to validate the proposed dynamic quantities within the considered simulation range. It is also concluded that the instantaneous air layer thickness, representing the air chamber pressure, and the bearing inlet flow rate are the key factors in determining the dynamic properties of the air layer. It is concluded that to evaluate the performance of the air caster seismic isolation device and increase the probability that the qualified seismic isolation performance will be exhibited, it is necessary to investigate which parameters are greatly involved in the viscous damping coefficient and the spring constant of  amass-spring-damper system equivalent to the air caster isolation system.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"1 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141816035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Seismic Analysis of G+20 RC Framed Structure Building for with and without Shear Walls","authors":"Dr Rohit Maheshwari","doi":"10.22146/jcef.12854","DOIUrl":"https://doi.org/10.22146/jcef.12854","url":null,"abstract":"The performance of High-rise Reinforced Concrete (R.C.) design buildings with the shear wall is targeted to provide stability, simplicity of maintenance, and durability of the framed structure. The impacts of lateral loads, axial forces, shear forces, base shear, maximum story drift, and tensile forces are common in high-rise structural systems. The present paper analyses G+20 story R.C. framed buildings for base shear, maximum story displacement and bending moment behaviour of structures with and without shear walls under seismic loading. The building is located in Dehradun, and the load has been considered as per I.S. code 1893:2016. Framed has been analysed using E-tabs to identify maximum base shear for the concern load conditions. The result shows that the frame designed with an appropriate shear wall absorbs more lateral forces, and minimum displacement values are induced and resist maximum moments throughout the height of the building when a structure is appropriately configured with a shear wall. The structure configured with the shear walls has high resistance to absorb earthquake forces compared to structures without shear walls.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"7 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141815391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Vulnerability Assessment of Regular and Vertically Irregular Residential Buildings in Nepal","authors":"Satish Paudel, Taufiq IIham Maulana IIham Maulana, H. Prayuda","doi":"10.22146/jcef.10316","DOIUrl":"https://doi.org/10.22146/jcef.10316","url":null,"abstract":"The need to assess the vulnerability of non-engineered residential RCC buildings in Nepal has become urgent, especially considering the ongoing modifications and additions to these structures without understanding their susceptibility to seismic events. Many residential buildings, particularly those up to three stories, did not fully comply to the guidelines outlined in Nepal Building Code NBC 105:2020. Therefore, there is a necessity to assess the seismic performance of these structures. This study aims to quantify the seismic vulnerability of such buildings by focusing on three distinct types: regular two and three-story structures, and irregular three-story structures. Using finite element modeling, the analysis of the buildings’ seismic capacity was performed through pushover analysis. Subsequently, linear time history analysis is conducted to determine the seismic demand. Two software were utilized to conduct the analyses, namely SAP2000 and STERA_3D. The study also includes the matching eleven strong ground motion inputs to Nepal’s site characteristics and response spectrum to ensure the relevance of the local context. Furthermore, fragility curves are constructed to compare the probability of structural failure, by first conducting the nonlinear dynamic analyses on the building specimens. The result showed that the probability of complete failure rises rapidly when an additional story is constructed with vertical irregularity, increasing from 1.8% to 5.7% in a non-engineered two-story building. The study also observes variations in top displacement across all three buildings due to differences in earthquake duration and frequency. From the findings, it is revealed that a significant increase in seismic vulnerability for vertically irregular buildings compared to regular ones","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"101 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140680353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study on the Effects of Helix Diameter and Spacing on the Helical Pile Axial Bearing Capacity in Cohesionless Soils","authors":"Ignatius Tommy Pratama, Anastasia Sri Lestari, Ivan Oktavianus","doi":"10.22146/jcef.7791","DOIUrl":"https://doi.org/10.22146/jcef.7791","url":null,"abstract":"The methods employed to calculate the axial bearing capacity of a helical pile depends on the shear failure model around the pile, which is also influenced by the spacing and diameter of the helical plates. However, studies on the transition of the failure mode and the load transfer mechanism with the change of helical plate spacing and diameter in cohesionless soil subjected to axial compressive load have been limited. Thus, this paper investigated the effects of helix diameter and spacing on the axial compressive load-bearing capacity, shear failure model, and load transfer mechanism of helical piles with two helical plates embedded in the homogeneous medium and dense sands, as well as in the stratified medium to very dense sand. Axial loading tests on helical piles with various helix diameters and spacings were simulated using a two-dimensional finite element program with axisymmetric modeling to obtain the load-settlement curve, which was later used to estimate the ultimate bearing capacity of the helical piles. The ultimate bearing capacity of the helical piles was also computed using the conventional methods, i.e., the individual bearing and cylindrical shear methods, and then compared to the numerical-based axial bearing capacity. The stress-strain behaviors of pile and soil were modeled using the Linear Elastic and Mohr-Coulomb material models, respectively. The results show that the numerical-based ultimate bearing capacity of a helical pile increased with increasing the diameter and spacing of the helix. However, the ultimate bearing capacity computed using conventional methods did not show this trend. Then, the transition from the cylindrical shear to the individual bearing failure mechanism occurred at a spacing ratio (i.e., helical plate spacing divided by its diameter) of about two. Ultimately, the load transfer curves indicate that the helical plates mainly supported the applied load.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140742590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Chloride Contaminant Transport in Tailings Storage Facility Dam (Case Study: Gold Mine in Sumatra)","authors":"Devina Pascayulinda, Budijanto Widjaja, Martin Wijaya","doi":"10.22146/jcef.9520","DOIUrl":"https://doi.org/10.22146/jcef.9520","url":null,"abstract":"In the practice of gold mining industry, hazardous waste known as tailings is produced during the ore extraction process. These tailings are typically stored in a dam structure called a Tailings Storage Facility (TSF). The planning and construction of a TSF are critical considerations, as the failure of a TSF can have substantial environmental impacts, pose risks to human safety, and result in industrial losses. Therefore, strict control is necessary in the development of TSFs to minimize the potential negative consequences. This research focuses on the transport of contaminants within a TSF, specifically examining the concentration of chloride contaminants and conducting particle movement analysis. The study utilizes modeling through the GeoStudio SEEP/W program to simulate groundwater flow profiles and the GeoStudio CTRAN/W program to understand contaminant movement over a 100-year period. GeoStudio modeling employs 10 materials: impermeable clay soil, filter sandy soil, transition gravel rock, three mine waste types (Fine, Rockfill, and Rockfill with fine), hard rock bedrock layer, in-situ soil representing the original layer, landslide with colluvial soil, and the tailings itself. Back analysis is employed to iterate model parameters and ensure modeling accuracy against field data, including comparisons with water quality test results and readings from vibrating wire piezometer (VWP) instrumentation. The contaminant transport is influenced by advection-dispersion processes and tends to concentrate within the TSF boundary toward the dam toe over a 100-year timeframe. The analysis emphasizes the influence of advection in contaminant transport and underscores the importance of particle position relative to the groundwater level, with Particle Tracking Analysis shows significant movement within the groundwater flow area. This research provides crucial insights into the dynamics of contaminant concentration, informing better decision-making in TSF planning and management. The findings underscore the imperative of strict control measures to minimize environmental impacts and human safety risks associated with TSFs, thereby advancing knowledge in gold mining waste management.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140744941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Pengga Reservoir in The Mandalika Special Economic Zone for Irrigation and Water Supply","authors":"D. Agastya, Wayan Yasa, Dewa Gede, Jaya Negara","doi":"10.22146/jcef.7913","DOIUrl":"https://doi.org/10.22146/jcef.7913","url":null,"abstract":"Mandalika Special Economic Zone is tourism area that is expected to improve the economy in West Nusa Tenggara Province. To support these activities, an allocation of domestic water needs of 200 liters second -1 is needed. The potential availability of water in the Pengga Reservoir is planned to be a source of domestic water needs in the Mandalika Special Economic Zone. Pengga Reservoir has an effective storage volume of 17.26 MCM. Potential water resources in Pengga Reservoir are obtained from reservoir outflow upstream and lateral inflow from several tributaries. The study was carried out to determine the reservoir storage capacity to meet domestic water needs and irrigation water needs covering an area 3189 ha. The cropping pattern used in the Pengga irrigation area is Paddy – Paddy/Secondary Crops – Paddy/Secondary Crops. To optimize the potential of water resources in the Pengga Reservoir, a linear programming optimization method is used. Indicators of the success of optimization calculations are indicated by the value of cropping intensity, k factor and reliability that have met the minimum limit value. The k factor value for irrigation water needs is 0.70 and domestic water needs is 0.85. Based on the optimization results, it is known the largest annual cropping intensity value occurs in the November I planting season. This conclusion can be seen from the comparison of annual cropping intensity values for the November I and November II planting schedules for the dry year inflow discharge scenario of 99.98% and 97.22% respectively. The cropping intensity value in the November I planting season is greater than November II, namely 100% and 97.25%, for the normal year discharge inflow scenario. This study provides an information for policy makers can use the November I planting schedule to obtain values for maximum cropping intensity and domestic water requirements.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"9 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140743752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water Quality Modelling with Industrial and Domestic Point Source Pollution : a Study Case of Cikakembang River, Majalaya District","authors":"Steven Kent, D. Yudianto, Cheng Gao, Finna Fitriana, Qian Wang","doi":"10.22146/jcef.11807","DOIUrl":"https://doi.org/10.22146/jcef.11807","url":null,"abstract":"Rapid industrial development is one of the leading causes of environmental degradation. The textile industries and the domestic activities in Majalaya District produce wastewater directly discharged into the Cikakembang River. As a result, the Cikakembang River’s water quality has decreased to the point that the water quality cannot be used for daily needs. This study modeled three main parameters in water quality modelling, namely Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD). Using MATLAB, the three-water quality governing equations originating from the Advection-Dispersion Equation were solved using the Runge Kutte-4 discretization scheme. The numerical modelling was carried out along 2.36 km of the Cikakembang River. All water quality coefficients, such as the DO Saturation (DOsat), the Reaeration Rate (ka), the Dispersion Coefficient (D), the Deoxygenation Rate (kd), and the Decomposition Rate (kc), for the Cikakembang River were estimated using equations developed by existing studies. The estimation of ka and D coefficients requires hydraulic parameters, which in this study were estimated using the HEC-RAS simulation. Meanwhile, kd and kc values were obtained from the calibration and verification process. The Relative Root Mean Square Error (RRMSE) objective function was used to evaluate the results of water quality modelling at three sampling points. In the calibration process, the resultsof water quality modelling produced RRMSE values for the DO, BOD, and COD parameters of 1.99%, 0.36% and 0.92%, respectively. Meanwhile, for the verification process, the RRMSE values for the DO, BOD, and COD parameters are 1.95%, 1.02% and 1.86%. All water quality parameters produce small RRMSE values in the calibration and verification processes. Hence, the water quality model created has good accuracy and stability.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"60 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping the Lava Flood Hazard Using the Flood Discharge Approach and 2D Hydrodynamic Modeling at the Rejali River, Mount Semeru","authors":"Akbar Bagus Prawira, Entin Hidayah, R. U. A. Wiyono","doi":"10.22146/jcef.8463","DOIUrl":"https://doi.org/10.22146/jcef.8463","url":null,"abstract":"In December 2021, Mount Semeru experienced an eruption accompanied by extreme rainfall, which resulted in lava floods, known as lahars or debris flows. The lava flood destroyed infrastructure, resulting in loss of life. Various rivers surrounding Mount Semeru, including the Rejali River, experienced the effects of this phenomenon. To address this, a study is needed to analyze the occurrence and frequency of lava floods over specific time intervals through the creation of a hazard map. This study aims to map the hazard of lava floods for various return periods using a coupled HEC-HMS and HEC-RAS software alongside a lava flood discharge approach. The HEC-HMS software is used to simulate hydrological processes, to obtain the lava flood discharge, while the HEC-RAS is used to model a two-dimensional (2D) lava flood hazard map. The input parameters of the modeling in this study are rainfall intensity, soil type, land cover, river distance, slope, and elevation. The results show that the flood area covers 9.55% of the total study area by 2 year return period (Q2), 11.80% by Q10, 14.10% by Q50, and 15.72% by Q200 with an overall validation Root Mean Square Error (RMSE) of 0.16. These changes are determined by the discharge volume from each return phase and the river's shallow depth, which causes overflow beyond the river's ability to accommodate the flow. Thus, this study suggests that the models successfully generated a reliable model for mapping the risk of lava floods on the Rejali River. These findings can help the government reduce disaster losses through adequate adaptation and mitigation initiatives.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140220085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incentives and Barriers to Green Building Implementation: The Case of Jakarta","authors":"Sigid Prasetyawan, R. Machfudiyanto, Titi Sari Nurul Rachmawati","doi":"10.22146/jcef.7150","DOIUrl":"https://doi.org/10.22146/jcef.7150","url":null,"abstract":"The low implementation of green building through building certification in Jakarta is responsible for the decreased achievement of reducing greenhouse gas emissions in 2020. This is observed in the energy sector through the efficient use of power in commercial buildings, which is only 37,789 tons (0.72 %) of the 5.26 million tons of CO2e expected in 2030, potentially causing the effects of a climate change-related disaster. In this case, the low prevalence of green buildings is due to the barriers preventing their implementation, with the provision of incentives being a suitable solution regarding its significant influence on rapid development. Therefore, this study aims to determine the influential relationship between barriers, incentives, and the level of green building implementation, to identify the most effective applicable benefits in Jakarta. In this context, path analysis and structural equation modeling (SEM) was used with 101 participants selected from developer/owner institutions, consultants, contractors, and the government experienced in implementing the experimental data of the buildings. These data were subsequently analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The results showed that cost-risk and knowledge-information barrier significantly impacted the level of green building implementation in Jakarta. This led to the recommendation of non-financial incentives as an effective regional benefit, which relevantly affected the level of green building implementation, as well as cost-risk and knowledge-information barriers. These results were expected to assist policymakers and practitioners in formulating effective incentive policies for the implementation of green buildings in Jakarta.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139356098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}