Hardiansyah, Wida Fitrianip, A. F. Edriani, Robi Hardiansyah, Rizka Lestyanti, L. Z. Mase
Evacuation is an important issue during the occurrence of an earthquake, due to the influence of people’s responsive behaviours to the disaster. This indicates the occurrence of overcrowded conditions, which causes the conflict of people’s movement. It is also one of the main reasons the process of evacuation is difficult, leading to the necessity to specifically model the movement within each building. Therefore, this study aims to analyze the earthquake evacuation modelling in Faculty of Engineering building, University of Bengkulu, Indonesia. This used a multi-agent programmable modelling environment known as NetLogo, which adopted an ABM model that is often utilized to observe elemental movement response. The agents occupying the building also moved to the stairs and evacuation doors, for exit towards the assembly point, which was located in front and behind Faculty of Engineering. The agent-based modelling is then conducted by inputting the layout of the building and the number of occupants in each room. Furthermore, the simulations were performed by considering various agents’ capacity in the building, during the evacuation. The results showed the time taken for the agents to exit the building during the disaster. This confirmed that the required exit time generally decreased with the increasing population percentage in the building. During this process, the conflict point also occurred around the corridor of Floors 1 and 2 (T1, T2 and T3), as well as the exits of the building (P1, P2, P3, and P4). This was due to the occurrence of a high density when agents carry out evacuation movements. Based on these results, the placement of signs was recommended, as guidelines during the evacuation process.
{"title":"Implementation of Agent Based Modelling to Observe the Evacuating Behavior at Faculty of Engineering Building, University of Bengkulu, Indonesia","authors":"Hardiansyah, Wida Fitrianip, A. F. Edriani, Robi Hardiansyah, Rizka Lestyanti, L. Z. Mase","doi":"10.22146/jcef.3589","DOIUrl":"https://doi.org/10.22146/jcef.3589","url":null,"abstract":"Evacuation is an important issue during the occurrence of an earthquake, due to the influence of people’s responsive behaviours to the disaster. This indicates the occurrence of overcrowded conditions, which causes the conflict of people’s movement. It is also one of the main reasons the process of evacuation is difficult, leading to the necessity to specifically model the movement within each building. Therefore, this study aims to analyze the earthquake evacuation modelling in Faculty of Engineering building, University of Bengkulu, Indonesia. This used a multi-agent programmable modelling environment known as NetLogo, which adopted an ABM model that is often utilized to observe elemental movement response. The agents occupying the building also moved to the stairs and evacuation doors, for exit towards the assembly point, which was located in front and behind Faculty of Engineering. The agent-based modelling is then conducted by inputting the layout of the building and the number of occupants in each room. Furthermore, the simulations were performed by considering various agents’ capacity in the building, during the evacuation. The results showed the time taken for the agents to exit the building during the disaster. This confirmed that the required exit time generally decreased with the increasing population percentage in the building. During this process, the conflict point also occurred around the corridor of Floors 1 and 2 (T1, T2 and T3), as well as the exits of the building (P1, P2, P3, and P4). This was due to the occurrence of a high density when agents carry out evacuation movements. Based on these results, the placement of signs was recommended, as guidelines during the evacuation process.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77797120","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}
This research simulated one-dimensional wave propagation by solving the shallow water equations using the Preissman implicit numerical scheme due to its ability to maintain simplicity and stability at a larger time step value. This numerical model was fundamentally developed to satisfy the shallow water condition, where the water depth or horizontal-length scale is much smaller than the free-surface disturbance wavelength or vertical-length scale, and to comprehensively test the accuracy of the model. Consequently, three different types of waves were considered and these include (1) tidal, (2) roll, and (3) solitary. In the first case, the model was proven to be robust and accurate due to its relatively-small errors for both water-surface elevation and velocity indicating that the Preismann scheme is suitable for longwave simulations. In the second case, it was fairly accurate in capturing the periodic permanent roll waves despite showing a higher water-surface elevation than the one observed and this discrepancy is due to the neglect of the turbulent Reynold stress in the model. Meanwhile, the last case showed remarkable discrepancies in the water-surface elevation because the dispersion effect is quite significant during the wave propagation. This indicates that the Preismann scheme underestimated the wave crest along with time when the dispersion term was neglected. All simulations were performed using the tridiagonal matrix algorithm, thereby eliminating the need for iterations for the solution of the Preismann scheme. The findings of this study are beneficial to the next generation of the Preissmann-scheme models which can be designed to include turbulence and dispersion terms.
{"title":"Numerical Simulation for One-Dimensional (1D) Wave Propagation by Solving the Shallow Water Equations using the Preissmann Implicit Scheme","authors":"Prilla Lidyana, B. Ginting, D. Yudianto","doi":"10.22146/jcef.3872","DOIUrl":"https://doi.org/10.22146/jcef.3872","url":null,"abstract":"This research simulated one-dimensional wave propagation by solving the shallow water equations using the Preissman implicit numerical scheme due to its ability to maintain simplicity and stability at a larger time step value. This numerical model was fundamentally developed to satisfy the shallow water condition, where the water depth or horizontal-length scale is much smaller than the free-surface disturbance wavelength or vertical-length scale, and to comprehensively test the accuracy of the model. Consequently, three different types of waves were considered and these include (1) tidal, (2) roll, and (3) solitary. In the first case, the model was proven to be robust and accurate due to its relatively-small errors for both water-surface elevation and velocity indicating that the Preismann scheme is suitable for longwave simulations. In the second case, it was fairly accurate in capturing the periodic permanent roll waves despite showing a higher water-surface elevation than the one observed and this discrepancy is due to the neglect of the turbulent Reynold stress in the model. Meanwhile, the last case showed remarkable discrepancies in the water-surface elevation because the dispersion effect is quite significant during the wave propagation. This indicates that the Preismann scheme underestimated the wave crest along with time when the dispersion term was neglected. All simulations were performed using the tridiagonal matrix algorithm, thereby eliminating the need for iterations for the solution of the Preismann scheme. The findings of this study are beneficial to the next generation of the Preissmann-scheme models which can be designed to include turbulence and dispersion terms.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90539662","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}
Palm oil has a great commercial value in the global vegetable oil market, due to having several beneficial uniqueness such as significant profits and high yields for farmers, as well as effective and efficient land use. As the second-largest producer of palm oil in the world, Malaysia produces an enormous amount of empty fruit bunch (EFB) as biomass waste, whose proper and improper disposal incurs costs and environmental problems, respectively. This EFB fibre is also used to produce bricks and mortar for building construction, due to being a sustainable solution to environmental problems. Therefore, this study aims to analyze the existing literature related to the application of EFB in the civil engineering field. This focused on the properties of the fibre and its effects on bricks and mortar, to gauge the challenges and prospects of EFB products in the local industry. EFB fibre is a porous voluminous cellulose structure, whose properties vary among each other due to diverse origins, species, and biological growth conditions. This is useful in reducing the weight and thermal conductivity of bricks, as well as slightly increasing their tensile and flexural strengths. However, some disadvantages were observed for the EFB bricks, with the workability and compressive strength being lower. The water absorption of this product was also higher than normal bricks. This confirmed that EFB fibre should be minimally used in bricks and mortar. As a natural fibre, concerns are often observed on inconsistent quality, poor fire resistance, and decay risk, which need to be solved before the use of bricks in the construction industry. This study recommends several patterns of improving the strength, quality, and consistency of EFB bricks, such as the alkaline treatment, which roughens the surface area of the product to enhance the fibre- atrix adhesion.
{"title":"The Advantages and Disadvantages of Palm Oil Empty Fruit Bunch on Bricks and Mortar","authors":"J. H. Ling, Yong Tat Lim, W. K. Leong, H. T. Sia","doi":"10.22146/jcef.3762","DOIUrl":"https://doi.org/10.22146/jcef.3762","url":null,"abstract":"Palm oil has a great commercial value in the global vegetable oil market, due to having several beneficial uniqueness such as significant profits and high yields for farmers, as well as effective and efficient land use. As the second-largest producer of palm oil in the world, Malaysia produces an enormous amount of empty fruit bunch (EFB) as biomass waste, whose proper and improper disposal incurs costs and environmental problems, respectively. This EFB fibre is also used to produce bricks and mortar for building construction, due to being a sustainable solution to environmental problems. Therefore, this study aims to analyze the existing literature related to the application of EFB in the civil engineering field. This focused on the properties of the fibre and its effects on bricks and mortar, to gauge the challenges and prospects of EFB products in the local industry. EFB fibre is a porous voluminous cellulose structure, whose properties vary among each other due to diverse origins, species, and biological growth conditions. This is useful in reducing the weight and thermal conductivity of bricks, as well as slightly increasing their tensile and flexural strengths. However, some disadvantages were observed for the EFB bricks, with the workability and compressive strength being lower. The water absorption of this product was also higher than normal bricks. This confirmed that EFB fibre should be minimally used in bricks and mortar. As a natural fibre, concerns are often observed on inconsistent quality, poor fire resistance, and decay risk, which need to be solved before the use of bricks in the construction industry. This study recommends several patterns of improving the strength, quality, and consistency of EFB bricks, such as the alkaline treatment, which roughens the surface area of the product to enhance the fibre- atrix adhesion.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89598102","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}
T. Rahman, B. Suhendro, W. Sartono, Purbolaras Nawangalam, H. Hardiyatmo
Airfield pavements begin a gradual deterioration from several sources, including traffic load and environmental conditions. To achieve its intended design life, routine maintenance, repair, and rehabilitation should be performed. There are considerable research and studies conducted on the design and practice of pavements rehabilitation/overlay for typical airfield pavements. However, most of the existing guidelines and studies are only suitable for pavements with conventional structures. There has been no detailed investigation into the practice of airfield asphalt overlay for non-conventional pavement structures, such as chicken claw /Cakar Ayam pavement system and nailed-slab system. In the present article, challenges and issues for airfield asphalt overlay design for non-conventional pavement structures were examined based on an actual runway rehabilitation project in one of the major airports in Indonesia in 2015. The overlay design procedure, the evaluation of the existing pavement condition, including visual surveys and deflection tests, and the pre-overlay treatments were also discussed. In addition, a finite element (FE) simulation to model the non-conventional pavement structure was developed to calculate the required overlay thickness. The result showed that, during the overlay design of non-conventional pavement structure, data from falling weight deflectometer (FWD) could not be directly used to estimate the back-calculated layers moduli because of the difference in the geometric features of the pavement structure. Moreover, the FE model can be a robust tool to simulate the complex three-dimensional geometric features of a non-conventional pavement and important loading conditions, such as interface shear bond of overlay, that are usually not available in other tools, such as FAARFIELD. Finally, this study showed that the additional asphalt overlay could reduce the fatigue stress at the bottom of the existing slab and vertical stress at the top of the subgrade, resulting in overall smaller stress levels
{"title":"Airfield Asphalt Overlay Design for Non-conventional Pavement Structures: A Case Study of Airport in Indonesia","authors":"T. Rahman, B. Suhendro, W. Sartono, Purbolaras Nawangalam, H. Hardiyatmo","doi":"10.22146/jcef.3771","DOIUrl":"https://doi.org/10.22146/jcef.3771","url":null,"abstract":"Airfield pavements begin a gradual deterioration from several sources, including traffic load and environmental conditions. To achieve its intended design life, routine maintenance, repair, and rehabilitation should be performed. There are considerable research and studies conducted on the design and practice of pavements rehabilitation/overlay for typical airfield pavements. However, most of the existing guidelines and studies are only suitable for pavements with conventional structures. There has been no detailed investigation into the practice of airfield asphalt overlay for non-conventional pavement structures, such as chicken claw /Cakar Ayam pavement system and nailed-slab system. In the present article, challenges and issues for airfield asphalt overlay design for non-conventional pavement structures were examined based on an actual runway rehabilitation project in one of the major airports in Indonesia in 2015. The overlay design procedure, the evaluation of the existing pavement condition, including visual surveys and deflection tests, and the pre-overlay treatments were also discussed. In addition, a finite element (FE) simulation to model the non-conventional pavement structure was developed to calculate the required overlay thickness. The result showed that, during the overlay design of non-conventional pavement structure, data from falling weight deflectometer (FWD) could not be directly used to estimate the back-calculated layers moduli because of the difference in the geometric features of the pavement structure. Moreover, the FE model can be a robust tool to simulate the complex three-dimensional geometric features of a non-conventional pavement and important loading conditions, such as interface shear bond of overlay, that are usually not available in other tools, such as FAARFIELD. Finally, this study showed that the additional asphalt overlay could reduce the fatigue stress at the bottom of the existing slab and vertical stress at the top of the subgrade, resulting in overall smaller stress levels","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72527192","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}
The density or concentration of mud is one of the key variables in studying cohesive sediments, due to being accumulated through settlement and consolidation, as well as resuspended through erosion. This indicates that the proper measurement of sediment density is important. Therefore, this study aims to evaluate the accuracy of density measurement by using the gamma-ray attenuation method as a non-intrusive technique. For Compton Scattering, gamma-ray attenuation was effectively independent of mineralogy, subsequently depending on only the electron density of the material, which is directly related to the bulk density of the mixture. Based on the results, the advantages of utilizing the nucleonic density gauge indicated that the technique was non-intrusive and very flexible for many experimental arrangements, as well as the high accuracy of measurements with errors less than 1%.
{"title":"Development of a Density Gauge for Measuring Water and Mud Density based on a Radioactive Technique","authors":"Aloysius Bagyo Widagdo","doi":"10.22146/jcef.3797","DOIUrl":"https://doi.org/10.22146/jcef.3797","url":null,"abstract":"The density or concentration of mud is one of the key variables in studying cohesive sediments, due to being accumulated through settlement and consolidation, as well as resuspended through erosion. This indicates that the proper measurement of sediment density is important. Therefore, this study aims to evaluate the accuracy of density measurement by using the gamma-ray attenuation method as a non-intrusive technique. For Compton Scattering, gamma-ray attenuation was effectively independent of mineralogy, subsequently depending on only the electron density of the material, which is directly related to the bulk density of the mixture. Based on the results, the advantages of utilizing the nucleonic density gauge indicated that the technique was non-intrusive and very flexible for many experimental arrangements, as well as the high accuracy of measurements with errors less than 1%.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79825069","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}
Ali Awaludin, Angga Fajar Setiawan, Imam Satyarno, Wu Shuanglan, Yusuf Haroki
This study aims to determine the finite element analysis of a BSPD-SHS (bi-directional shear panel damper with a square hollow section) device, to dissipate the seismic excitation energy through the lateral relative displacement between the pier and girder of the simple support bridge. The configuration of the square hollow section is also performed for a double role, such as web panel and flange, indicating the expectations to reduce the seismic force within the lateral and longitudinal directions. In the preliminary development phase, the finite element analysis was conducted under monotonic loading, to examine the skeleton curve characteristics and internal stress action on resisting seismic force. The characteristics of this curve include elastic stiffness, shear strength, post-yield behavior, and internal stress distributions. Based on the evaluation of the BSPD-SHS slenderness effect, the variation of depth-thickness ratio was considered between 25 to 67. To investigate the fitness of the theoretical shear strength formulation, two different hardening roles of the metal plasticity model were subsequently compared in this study, including the elastic-perfectly plastic and isotropic/kinematic techniques. Furthermore, the effect of the restrained degree of freedom idealization on the top base plate was captured. This indicated that all specimens model with the restrained top base plate achieved stable post-yield stiffness. In implementing the unrestrained top base plate, this stiffness was achieved when the web slenderness ratio equaled 25. The differences observed between the hardening roles also generated a slight yield shear strength discrepancy. However, significant differences occurred in the post-yield shear strength. The shear resistance proportion of the stress components was also accurately quantified with an analytical stress integration. Based on the restrained top base plate, the flange tension field generated a significant contribution to the post-yield shear resistance.
{"title":"Finite Element Analysis of Bi-directional Shear Panel Damper with Square Hollow Section under Monotonic Loading","authors":"Ali Awaludin, Angga Fajar Setiawan, Imam Satyarno, Wu Shuanglan, Yusuf Haroki","doi":"10.22146/jcef.3842","DOIUrl":"https://doi.org/10.22146/jcef.3842","url":null,"abstract":"This study aims to determine the finite element analysis of a BSPD-SHS (bi-directional shear panel damper with a square hollow section) device, to dissipate the seismic excitation energy through the lateral relative displacement between the pier and girder of the simple support bridge. The configuration of the square hollow section is also performed for a double role, such as web panel and flange, indicating the expectations to reduce the seismic force within the lateral and longitudinal directions. In the preliminary development phase, the finite element analysis was conducted under monotonic loading, to examine the skeleton curve characteristics and internal stress action on resisting seismic force. The characteristics of this curve include elastic stiffness, shear strength, post-yield behavior, and internal stress distributions. Based on the evaluation of the BSPD-SHS slenderness effect, the variation of depth-thickness ratio was considered between 25 to 67. To investigate the fitness of the theoretical shear strength formulation, two different hardening roles of the metal plasticity model were subsequently compared in this study, including the elastic-perfectly plastic and isotropic/kinematic techniques. Furthermore, the effect of the restrained degree of freedom idealization on the top base plate was captured. This indicated that all specimens model with the restrained top base plate achieved stable post-yield stiffness. In implementing the unrestrained top base plate, this stiffness was achieved when the web slenderness ratio equaled 25. The differences observed between the hardening roles also generated a slight yield shear strength discrepancy. However, significant differences occurred in the post-yield shear strength. The shear resistance proportion of the stress components was also accurately quantified with an analytical stress integration. Based on the restrained top base plate, the flange tension field generated a significant contribution to the post-yield shear resistance.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87971452","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}
KARDAS is an area used to protect groundwater from its usage as a water source. Meanwhile, the recharge zone is normally determined in Indonesia through the Regulation of the Ministry of Public Works and Housing (Permen PUPR) Number 10/2015 with the focus on certain physical parameters such as soil texture, land use/land cover, annual rainfall, and slope provided with relative potency values from 1 which represents very low to 5 which is very high. This system was used to review four parameters in a small grid unit of 1 km2 each in the Cisadane River Basin with a 1,545.47 km2 area divided into 1,710 units and the most dominant grid placed at the middle part while the rest are at the edge of the basin. This research focused on the clarification methods to determine the potential recharge variables for this river basin in order to serve as a reference for the potential recharge zone in Indonesia. The KARDAS map obtained showed a very high potential with a score of 17-20 covering 183 km2 (10.45%), high potential with a score of 13-16 involving 943 km2 (56.96%), medium potential with 584 km2 (32.59%), and 0 small potential. Moreover, KARDAS desk study results were clarified using the field or ground test to ensure accuracy and this involved using 14 units as samples to represent the five potentials through temporary quantitative cumulative scores. The desk study or secondary data results were found to be only 50% accurate with a limited point survey but the application of qualitative perception showed that only 1 point does not match with the medium and high potentials this indicates the accuracy was 93% which is categorized to be good.
{"title":"Clarification of Watershed Recharge in Cisadane River Basin through Ground Test","authors":"Dina P.A Hidayat, Sri Legowo W. D, Mohammad Farid","doi":"10.22146/jcef.4015","DOIUrl":"https://doi.org/10.22146/jcef.4015","url":null,"abstract":"KARDAS is an area used to protect groundwater from its usage as a water source. Meanwhile, the recharge zone is normally determined in Indonesia through the Regulation of the Ministry of Public Works and Housing (Permen PUPR) Number 10/2015 with the focus on certain physical parameters such as soil texture, land use/land cover, annual rainfall, and slope provided with relative potency values from 1 which represents very low to 5 which is very high. This system was used to review four parameters in a small grid unit of 1 km2 each in the Cisadane River Basin with a 1,545.47 km2 area divided into 1,710 units and the most dominant grid placed at the middle part while the rest are at the edge of the basin. This research focused on the clarification methods to determine the potential recharge variables for this river basin in order to serve as a reference for the potential recharge zone in Indonesia. The KARDAS map obtained showed a very high potential with a score of 17-20 covering 183 km2 (10.45%), high potential with a score of 13-16 involving 943 km2 (56.96%), medium potential with 584 km2 (32.59%), and 0 small potential. Moreover, KARDAS desk study results were clarified using the field or ground test to ensure accuracy and this involved using 14 units as samples to represent the five potentials through temporary quantitative cumulative scores. The desk study or secondary data results were found to be only 50% accurate with a limited point survey but the application of qualitative perception showed that only 1 point does not match with the medium and high potentials this indicates the accuracy was 93% which is categorized to be good.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80887157","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}
Aryanti Karlina Nurendyastuti, Mochamad Mardi Marta Dinata, Arumjeni Mitayani, Muhammad Rizki Purnama, Mohammad Bagus Adityawan, Mohammad Farid, Arno Adi Kuntoro, Widyaningtias
Tsunami buoy, linked to satellite, is commonly used as a tsunami early warning system but has been discovered to have several drawbacks such as the need for approximately 5 minutes to issue an early warning for a tsunami after detecting the initial wave as well as its fragility. It was also reported that the twenty-two buoys placed in the Indonesian seas from 2012 to 2018 were damaged and missing. Therefore, this study proposes a new method for tsunami early warning by integrating ship-to-ship maritime wireless communication. It is important to note that vessels or fishing boats with over 30 GT have the ability to travel more than 100 nmi (approximately 180 km) from the shoreline and can be equipped with point-to-multipoint VHF radio communication. Meanwhile, smaller boats on the fishing ground located approximately 2-5 km from the shore can use a WiFi network to communicate like a wireless mesh while the existing terrestrial network can be used for the ship-to-shore communication between boats and land stations. This system is expected to provide significant benefits for a fishing town such as Pangandaran, West Java, Indonesia which is directly facing Java Megathrust in the Indian Ocean. Therefore, a tsunami numerical simulation was conducted in this study using Shallow Water Equation which involved a hypothetical tsunami simulated from the possible fault source which is approximately 250 km from the source. Moreover, the vessel’s location was assumed to be in line with the fishing ground while the arrival time of the tsunami was estimated from the model to be 22.5 minutes and compared to the relay time of the proposed system which was approximately 5.4 seconds. This is faster in terms of delay than the existing system which relays information through satellite at approximately 5 minutes in an ideal condition and also has the ability to reduce the need for tsunami buoys.
{"title":"Tsunami Early Warning System Based on Maritime Wireless Communication","authors":"Aryanti Karlina Nurendyastuti, Mochamad Mardi Marta Dinata, Arumjeni Mitayani, Muhammad Rizki Purnama, Mohammad Bagus Adityawan, Mohammad Farid, Arno Adi Kuntoro, Widyaningtias","doi":"10.22146/jcef.2878","DOIUrl":"https://doi.org/10.22146/jcef.2878","url":null,"abstract":"Tsunami buoy, linked to satellite, is commonly used as a tsunami early warning system but has been discovered to have several drawbacks such as the need for approximately 5 minutes to issue an early warning for a tsunami after detecting the initial wave as well as its fragility. It was also reported that the twenty-two buoys placed in the Indonesian seas from 2012 to 2018 were damaged and missing. Therefore, this study proposes a new method for tsunami early warning by integrating ship-to-ship maritime wireless communication. It is important to note that vessels or fishing boats with over 30 GT have the ability to travel more than 100 nmi (approximately 180 km) from the shoreline and can be equipped with point-to-multipoint VHF radio communication. Meanwhile, smaller boats on the fishing ground located approximately 2-5 km from the shore can use a WiFi network to communicate like a wireless mesh while the existing terrestrial network can be used for the ship-to-shore communication between boats and land stations. This system is expected to provide significant benefits for a fishing town such as Pangandaran, West Java, Indonesia which is directly facing Java Megathrust in the Indian Ocean. Therefore, a tsunami numerical simulation was conducted in this study using Shallow Water Equation which involved a hypothetical tsunami simulated from the possible fault source which is approximately 250 km from the source. Moreover, the vessel’s location was assumed to be in line with the fishing ground while the arrival time of the tsunami was estimated from the model to be 22.5 minutes and compared to the relay time of the proposed system which was approximately 5.4 seconds. This is faster in terms of delay than the existing system which relays information through satellite at approximately 5 minutes in an ideal condition and also has the ability to reduce the need for tsunami buoys.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"15 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72472770","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}
Wen Kam Leong, Alex Lung Keat Ngo, Alvin Choon Hsien Wong, Jen Hua Ling, How Teck Sia
Underground septic tanks are the most common and conventional primary black water treatment adopted by local households in Sarawak. To ensure its usefulness, periodic mandatory desludging or emptying of the various types of rateable holdings was enforced from 1998. The current mandatory desludging frequency is 4 years for residential households, although its effectiveness is still not clear, substantial annual finance and subsidies are being allocated by the Sarawak State Government. In this study, the underground septic tanks in Sibu located in residential areas in Sarawak, East Malaysia, were evaluated quantitatively based on the measured faecal sludge with a known retention time in respect to the regulated desludging frequency. Furthermore, various problems were encountered during the initial measurement carried out by sludge judge which typically used by the wastewater treatment and chemical plants. A modified PVC pipe was proposed to overcome these observed problems. This has greatly improved the measurement time and substantially reduced unwanted impediments for the contractor during desludging. The back analysis results showed that the recommended desludging frequency based on the ratio of total sludge and scum to the effective working volume in 30% and 50% thresholds for residential areas were 3.82 and 6.36 years, respectively. Furthermore, it was discovered that there was a potential to adjust the existing mandatory 4 years desludging frequency to a longer period for cost-effective consideration. This study is strictly on the physical quantity measurement of sludge and scum volumes for the known retention times. The complex influences of microbiological activities, micro-environmental factors and sizes or geometries of septic tanks for faecal sludge production were not considered.
{"title":"The Mandatory 4 Years Desludging Frequency of Underground Septic Tanks in Residential Areas: A Case Study in Sibu Sarawak, East Malaysia","authors":"Wen Kam Leong, Alex Lung Keat Ngo, Alvin Choon Hsien Wong, Jen Hua Ling, How Teck Sia","doi":"10.22146/jcef.3812","DOIUrl":"https://doi.org/10.22146/jcef.3812","url":null,"abstract":" Underground septic tanks are the most common and conventional primary black water treatment adopted by local households in Sarawak. To ensure its usefulness, periodic mandatory desludging or emptying of the various types of rateable holdings was enforced from 1998. The current mandatory desludging frequency is 4 years for residential households, although its effectiveness is still not clear, substantial annual finance and subsidies are being allocated by the Sarawak State Government. In this study, the underground septic tanks in Sibu located in residential areas in Sarawak, East Malaysia, were evaluated quantitatively based on the measured faecal sludge with a known retention time in respect to the regulated desludging frequency. Furthermore, various problems were encountered during the initial measurement carried out by sludge judge which typically used by the wastewater treatment and chemical plants. A modified PVC pipe was proposed to overcome these observed problems. This has greatly improved the measurement time and substantially reduced unwanted impediments for the contractor during desludging. The back analysis results showed that the recommended desludging frequency based on the ratio of total sludge and scum to the effective working volume in 30% and 50% thresholds for residential areas were 3.82 and 6.36 years, respectively. Furthermore, it was discovered that there was a potential to adjust the existing mandatory 4 years desludging frequency to a longer period for cost-effective consideration. This study is strictly on the physical quantity measurement of sludge and scum volumes for the known retention times. The complex influences of microbiological activities, micro-environmental factors and sizes or geometries of septic tanks for faecal sludge production were not considered.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83742291","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}
The Cikapundung river basin community uses the Cibarani channel as a drainage system and water source for fishing. However, the test result released on 9th November 2020 revealed that the channel’s water quality failed to reach the class II raw water standards due to various domestic waste discharges. This led to the performance of various studies to identify pollution control techniques by limiting the wastewater discharge and quality, controlling the intake discharge, and using baffles. The Cibarani channel has a drop-structure that can improve the water quality, though the effect has not been previously detailed. Therefore, this study was intended to comprehensively examine the effect of the drop-structure along the Cibarani channel to improve water quality conditions, specifically the Dissolved Oxygen (DO) parameter. This study employed the one-dimensional HEC-RAS software to simulate the hydrodynamic and water quality conditions along the Cibarani channel, and the drop-structure was modelled using two alternatives consisting of a vertical wall and a steep riverbed. Subsequently, the drop-structure fitted with a vertical wall gave a more plausible reaeration rate of 125 day-1 and Root Mean Square Error (RMSE) value of 0.50. The placement of a similar configuration before the first housing of the channel increased the DO concentrations by an average of 4.37 mg/L. This was followed by the modelling of another drop-structure after the first housing to increase the DO levels at the downstream part. Eventually, the combination of the two new drop-structures succeeded in increasing the DO concentrations along the Cibarani channel to 3.3 - 6.9 mg/L.
奇卡朋东河流域社区使用奇巴拉尼水道作为排水系统和捕鱼水源。然而，2020年11月9日公布的检测结果显示，由于各种生活垃圾的排放，该渠道的水质未达到II类原水标准。这导致了各种研究的表现，通过限制废水排放和质量，控制进水口排放和使用挡板来确定污染控制技术。西巴拉尼水道有一个水滴结构，可以改善水质，尽管之前没有详细的效果。因此，本研究旨在综合考察沿Cibarani通道的水滴结构对改善水质条件，特别是溶解氧(DO)参数的影响。本研究采用一维HEC-RAS软件模拟了Cibarani河道的水动力和水质条件，并采用垂直墙和陡峭河床两种方案对水滴结构进行了模拟。结果表明，采用垂直壁面的滴落结构的再生速率为125 d -1，均方根误差(RMSE)为0.50。在通道的第一个外壳之前放置类似的配置，使DO浓度平均增加4.37 mg/L。接下来是在第一个壳体之后的另一个水滴结构的建模，以增加下游部分的DO水平。最终，两种新的滴状结构的结合成功地将Cibarani通道沿线的DO浓度提高到3.3 - 6.9 mg/L。
{"title":"The Use of Drop-Structures to Increase the Dissolved Oxygen Level along the Cibarani Channel","authors":"Jonathan Wijaya, Doddi Yudianto, Finna Fitriana","doi":"10.22146/jcef.3603","DOIUrl":"https://doi.org/10.22146/jcef.3603","url":null,"abstract":"The Cikapundung river basin community uses the Cibarani channel as a drainage system and water source for fishing. However, the test result released on 9th November 2020 revealed that the channel’s water quality failed to reach the class II raw water standards due to various domestic waste discharges. This led to the performance of various studies to identify pollution control techniques by limiting the wastewater discharge and quality, controlling the intake discharge, and using baffles. The Cibarani channel has a drop-structure that can improve the water quality, though the effect has not been previously detailed. Therefore, this study was intended to comprehensively examine the effect of the drop-structure along the Cibarani channel to improve water quality conditions, specifically the Dissolved Oxygen (DO) parameter. This study employed the one-dimensional HEC-RAS software to simulate the hydrodynamic and water quality conditions along the Cibarani channel, and the drop-structure was modelled using two alternatives consisting of a vertical wall and a steep riverbed. Subsequently, the drop-structure fitted with a vertical wall gave a more plausible reaeration rate of 125 day-1 and Root Mean Square Error (RMSE) value of 0.50. The placement of a similar configuration before the first housing of the channel increased the DO concentrations by an average of 4.37 mg/L. This was followed by the modelling of another drop-structure after the first housing to increase the DO levels at the downstream part. Eventually, the combination of the two new drop-structures succeeded in increasing the DO concentrations along the Cibarani channel to 3.3 - 6.9 mg/L.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84541268","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}
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