Sonia Oktariyanti, Entin Hidayah, Saifurridzal, M. F. Ma’ruf, N. Hayati, Zulkifli Yusop
Volcanic mudflow floods occur when rainfall runoff combines with volcanic material and flows downstream. These devastating events cause significant damage to infrastructure, disrupt economies, and result in injuries and casualties. One area where the flow of volcanic material greatly affects the situation is the Rejali River, which receives a substantial amount of volcanic debris from Mount Semeru. To address this issue and begin mitigating the associated risks, it is crucial to start by mapping the potential distribution of volcanic mudflow floods. Therefore, this study aimed to assess factors impacting volcanic mudflow flood susceptibility and to create a corresponding susceptibility map. The study employed the Analytical Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to determine the influence of various factors and classify the areas, respectively. These methods were integrated with the Geographic Information System (GIS) to enhance the analysis. The weighted analysis results showed that the most impactful factors conditioning volcanic mudflow floods, in descending order, were rainfall (42.40%), land cover (13.89%), elevation (13.39%), slope (12.51%), distance from the river (7.09%), soil type (6.58%), and rock distribution (4.13%). The TOPSIS calculation further highlighted that rainfall intensity between 104.03 and 109.65 mm day-1 had the greatest influence on susceptibility. The successful integration of AHP and TOPSIS methods with GIS helped develop a volcanic mudflow flood susceptibility model with an outstanding accuracy of 0.969. The model showed that approximately 46.40% of the areas along the Rejali River exhibited very high susceptibility to volcanic mudflow floods, while an additional 16.21% indicated high susceptibility and substantial risk in most regions. Therefore, the generated susceptibility map offered important insights for shaping future mitigation strategies and influencing policy decisions.
{"title":"Mapping of Mount Semeru Volcanic Mudflow Susceptibility Along the Rejali River using the GIS-based AHP-TOPSIS Ensemble Approach","authors":"Sonia Oktariyanti, Entin Hidayah, Saifurridzal, M. F. Ma’ruf, N. Hayati, Zulkifli Yusop","doi":"10.22146/jcef.6691","DOIUrl":"https://doi.org/10.22146/jcef.6691","url":null,"abstract":"Volcanic mudflow floods occur when rainfall runoff combines with volcanic material and flows downstream. These devastating events cause significant damage to infrastructure, disrupt economies, and result in injuries and casualties. One area where the flow of volcanic material greatly affects the situation is the Rejali River, which receives a substantial amount of volcanic debris from Mount Semeru. To address this issue and begin mitigating the associated risks, it is crucial to start by mapping the potential distribution of volcanic mudflow floods. Therefore, this study aimed to assess factors impacting volcanic mudflow flood susceptibility and to create a corresponding susceptibility map. The study employed the Analytical Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to determine the influence of various factors and classify the areas, respectively. These methods were integrated with the Geographic Information System (GIS) to enhance the analysis. The weighted analysis results showed that the most impactful factors conditioning volcanic mudflow floods, in descending order, were rainfall (42.40%), land cover (13.89%), elevation (13.39%), slope (12.51%), distance from the river (7.09%), soil type (6.58%), and rock distribution (4.13%). The TOPSIS calculation further highlighted that rainfall intensity between 104.03 and 109.65 mm day-1 had the greatest influence on susceptibility. The successful integration of AHP and TOPSIS methods with GIS helped develop a volcanic mudflow flood susceptibility model with an outstanding accuracy of 0.969. The model showed that approximately 46.40% of the areas along the Rejali River exhibited very high susceptibility to volcanic mudflow floods, while an additional 16.21% indicated high susceptibility and substantial risk in most regions. Therefore, the generated susceptibility map offered important insights for shaping future mitigation strategies and influencing policy decisions.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355679","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}
Kukuh Adhi Kafie, A. Triwiyono, Iman Satyarno, Hsuan-Teh Hu
The adequacy of the structural performance of a wharf in withstanding seismic loads is of paramount importance. Therefore, this research aims to conduct an accurate pushover analysis on the adequacy of a wharf located in North Sulawesi, Indonesia. The study provides a comprehensive overview of the seismic performance of the wharf by examining displacement and strain parameters of its plastic hinge components under various loading conditions. To simulate accidental torsion, the wharf structure was analyzed by introducing variations in the eccentricity offset of the lateral pushover load of -5%, 0%, and 5% from the center of mass. The analysis of the torsion behavior involved a comprehensive examination of four control points located at each corner of the wharf plan. Additionally, the investigation took into account, the crucial aspect of soil-structure interaction by considering the equivalent fixity depth of the pile, which was used to evaluate the fixity length of the structure. In order to determine the target displacement of the wharf, analysis was performed in accordance with the established methodologies outlined in FEMA 356. It is also important to note that the seismic performance of the wharf was evaluated based on acceptance criteria in the form of strain limits imposed on various components, including concrete elements, reinforcing steel, and steel pipes, as prescribed by ASCE 61-14. In this study, a total of 30 models were examined, and the obtained results showed that the structure exhibited controlled and repairable damage even when subjected to a 475-year earthquake return period (CLE: Contingency Level Earthquake). Following this, the analysis of variations in displacement control point served to determine the inherent torsion exhibited by the structure, and the introduction of different lateral load eccentricity offsets and variations in pushover loading direction were found to contribute to the increased displacement and strain in the plastic hinge components.
{"title":"Seismic Performance Evaluation of Wharf Based on ASCE 61-14","authors":"Kukuh Adhi Kafie, A. Triwiyono, Iman Satyarno, Hsuan-Teh Hu","doi":"10.22146/jcef.6749","DOIUrl":"https://doi.org/10.22146/jcef.6749","url":null,"abstract":"The adequacy of the structural performance of a wharf in withstanding seismic loads is of paramount importance. Therefore, this research aims to conduct an accurate pushover analysis on the adequacy of a wharf located in North Sulawesi, Indonesia. The study provides a comprehensive overview of the seismic performance of the wharf by examining displacement and strain parameters of its plastic hinge components under various loading conditions. To simulate accidental torsion, the wharf structure was analyzed by introducing variations in the eccentricity offset of the lateral pushover load of -5%, 0%, and 5% from the center of mass. The analysis of the torsion behavior involved a comprehensive examination of four control points located at each corner of the wharf plan. Additionally, the investigation took into account, the crucial aspect of soil-structure interaction by considering the equivalent fixity depth of the pile, which was used to evaluate the fixity length of the structure. In order to determine the target displacement of the wharf, analysis was performed in accordance with the established methodologies outlined in FEMA 356. It is also important to note that the seismic performance of the wharf was evaluated based on acceptance criteria in the form of strain limits imposed on various components, including concrete elements, reinforcing steel, and steel pipes, as prescribed by ASCE 61-14. In this study, a total of 30 models were examined, and the obtained results showed that the structure exhibited controlled and repairable damage even when subjected to a 475-year earthquake return period (CLE: Contingency Level Earthquake). Following this, the analysis of variations in displacement control point served to determine the inherent torsion exhibited by the structure, and the introduction of different lateral load eccentricity offsets and variations in pushover loading direction were found to contribute to the increased displacement and strain in the plastic hinge components.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355882","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 bearing capacity of shallow foundations on soft soils can generally be estimated based on Local Shear Failure (Terzaghi theory). Several researchers previously stated that the installation of micro-piles on the failure area (slide) can increase the shear strength of the soil. This can be followed up by providing micro-pile reinforcement to prevent lateral soil movement. Therefore, this research was conducted to increase the bearing capacity of shallow foundations on medium-consistency soft clay soils that have been reinforced with micro piles. The research was conducted using modeling in the laboratory with a scale of 1:30. The soil sample used was kaolin clay made from slurry made from kaolin powder with a water content (wc = 1.77 LL), liquid limit (LL = 62.35%) and sample diameter (d = 33 cm). The slurry was formed by compacting at a medium consistency level with an undrained cohesion value (cu = 0.397 kg cm-2). The micro-pile material in the form of apus bamboo was installed, varying in diameter (d) 0.2 cm (0.027 B), 0.3 cm (0.04 B), and 0.5 cm (0.07 B); sum (n) 4, 9, 16, and 25; and length (L) 10 cm (1.33B), 13 cm (1.73B), and 16 cm (2.13B) micro-piles. While the foundation model uses a squarefoundation B x B with B = 7.5 cm. The tests were carried out before and after the micro-piles were reinforced with a soil shear failure test. The results showed that a decrease of 0.1B caused an increase in the ultimate bearing capacity of the micro-pile (qult-empirical, 0.1B) from the ultimate bearing capacity before installing the micro-pile. This value is then used to determine the ultimate bearing capacity ratio so that Rq,0.1B = qult-empirical,0.1B/qult-Terzaghi with the optimum bearing capacity ratio occurring at Rq,0.1B with n3 = 16, d2 = 0.04B, L2 = 1.73B.
{"title":"Increasing the Bearing Capacity of Shallow Foundations on Soft Soil After the Installation of Micro-Piles","authors":"Isnaniati, I. B. Mochtar","doi":"10.22146/jcef.5925","DOIUrl":"https://doi.org/10.22146/jcef.5925","url":null,"abstract":"The bearing capacity of shallow foundations on soft soils can generally be estimated based on Local Shear Failure (Terzaghi theory). Several researchers previously stated that the installation of micro-piles on the failure area (slide) can increase the shear strength of the soil. This can be followed up by providing micro-pile reinforcement to prevent lateral soil movement. Therefore, this research was conducted to increase the bearing capacity of shallow foundations on medium-consistency soft clay soils that have been reinforced with micro piles. The research was conducted using modeling in the laboratory with a scale of 1:30. The soil sample used was kaolin clay made from slurry made from kaolin powder with a water content (wc = 1.77 LL), liquid limit (LL = 62.35%) and sample diameter (d = 33 cm). The slurry was formed by compacting at a medium consistency level with an undrained cohesion value (cu = 0.397 kg cm-2). The micro-pile material in the form of apus bamboo was installed, varying in diameter (d) 0.2 cm (0.027 B), 0.3 cm (0.04 B), and 0.5 cm (0.07 B); sum (n) 4, 9, 16, and 25; and length (L) 10 cm (1.33B), 13 cm (1.73B), and 16 cm (2.13B) micro-piles. While the foundation model uses a squarefoundation B x B with B = 7.5 cm. The tests were carried out before and after the micro-piles were reinforced with a soil shear failure test. The results showed that a decrease of 0.1B caused an increase in the ultimate bearing capacity of the micro-pile (qult-empirical, 0.1B) from the ultimate bearing capacity before installing the micro-pile. This value is then used to determine the ultimate bearing capacity ratio so that Rq,0.1B = qult-empirical,0.1B/qult-Terzaghi with the optimum bearing capacity ratio occurring at Rq,0.1B with n3 = 16, d2 = 0.04B, L2 = 1.73B.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139356025","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}
D. C. Istiyanto, Ika Wulandari, Shafan A. Aziiz, Rizaldi C. Yuniardi, Yofan T.D Suranto, Affandy Harita, Aloysius B Hamid, Widagdo
A prospective resolution to the intricate predicaments of flooding, sanitation, and the availability of unprocessed water for the populace of Jakarta residents is the implementation of the coastal reservoir paradigm. This paradigm entails harnessing the latent capacity of the Cisadane River flow and its subsequent storage within a retention pond, and then subjecting it to reprocessing to serve as a viable source of raw water. The selection of a vertical seawall design was based on the objective of creating an effective barrier between the reservoir and the sea, while also considering several environmental factors. This design was selected with the aim of minimizing the need for extensive soil excavation and rock placement. However, it is important to note that the risks of construction failure associated with seepage under hydraulic structure and dam stability pose significant challenges. Besides preventing saltwater intrusion and maintaining the integrity of the reservoir as a freshwater source, dam must be designed to mitigate potential seepage failure and intrusion issues. To address these concerns, this study employed numerical simulation using the SEEP/W and CTRAN/W software. The simulation was carried out to analyze seepage discharge under a vertical dam and predict potential seawater intrusion into the reservoir. The dam was examined over a ten-year period, with varying embankment widths of 10m, 20m, and 30m. The analysis considered changes in water level (ΔH) and the addition of a cut-off wall at depths of 5m, 10m, and 15m. The obtained results showed that seepage discharge rates amounted to 3,14x10-4 m3 s-1, 2,67x10-4 m3 s-1, and 2,50x10-4 m3 s-1 for embankment widths of 10m, 20m, and 30m, respectively, under a 1m level difference condition. Following this, the safety factor for piping on vertical embankment was determined as 1.10, 1.34, and 1.39 for widths of 10m, 20m, and 30m, respectively. This factor was found to increase to 4.03 when the embankment distance was widened, and a 15m deep cut-off wall was installed. It is important to note that the seawater intrusion model predicted a seawater concentration of 65,12 g m-3 at the bottom for an embankment width of 10m, while no intrusion was observed at widths of 20m and 30m with ΔH=1m. This study aims to assess potential risks of piping due to seepage and seawater contamination at the Cisadane Estuary.
{"title":"Seepage Analysis and the Reservoir Water Pollution Potential under Vertical Dam Structure Planning","authors":"D. C. Istiyanto, Ika Wulandari, Shafan A. Aziiz, Rizaldi C. Yuniardi, Yofan T.D Suranto, Affandy Harita, Aloysius B Hamid, Widagdo","doi":"10.22146/jcef.6266","DOIUrl":"https://doi.org/10.22146/jcef.6266","url":null,"abstract":"A prospective resolution to the intricate predicaments of flooding, sanitation, and the availability of unprocessed water for the populace of Jakarta residents is the implementation of the coastal reservoir paradigm. This paradigm entails harnessing the latent capacity of the Cisadane River flow and its subsequent storage within a retention pond, and then subjecting it to reprocessing to serve as a viable source of raw water. The selection of a vertical seawall design was based on the objective of creating an effective barrier between the reservoir and the sea, while also considering several environmental factors. This design was selected with the aim of minimizing the need for extensive soil excavation and rock placement. However, it is important to note that the risks of construction failure associated with seepage under hydraulic structure and dam stability pose significant challenges. Besides preventing saltwater intrusion and maintaining the integrity of the reservoir as a freshwater source, dam must be designed to mitigate potential seepage failure and intrusion issues. To address these concerns, this study employed numerical simulation using the SEEP/W and CTRAN/W software. The simulation was carried out to analyze seepage discharge under a vertical dam and predict potential seawater intrusion into the reservoir. The dam was examined over a ten-year period, with varying embankment widths of 10m, 20m, and 30m. The analysis considered changes in water level (ΔH) and the addition of a cut-off wall at depths of 5m, 10m, and 15m. The obtained results showed that seepage discharge rates amounted to 3,14x10-4 m3 s-1, 2,67x10-4 m3 s-1, and 2,50x10-4 m3 s-1 for embankment widths of 10m, 20m, and 30m, respectively, under a 1m level difference condition. Following this, the safety factor for piping on vertical embankment was determined as 1.10, 1.34, and 1.39 for widths of 10m, 20m, and 30m, respectively. This factor was found to increase to 4.03 when the embankment distance was widened, and a 15m deep cut-off wall was installed. It is important to note that the seawater intrusion model predicted a seawater concentration of 65,12 g m-3 at the bottom for an embankment width of 10m, while no intrusion was observed at widths of 20m and 30m with ΔH=1m. This study aims to assess potential risks of piping due to seepage and seawater contamination at the Cisadane Estuary.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355654","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 Wonogiri Reservoir is a multipurpose reservoir at the Upper Bengawan Solo Watershed, primarily designed to serve as a flood control system. However, there is no accurate estimation of the inflow into the reservoir due to the limited availability of hydrological stations. Observations showed only four out of ten unit hydrographs of the Wonogiri Reservoir watershed. Therefore, this study was conducted to apply an integrated similarity-based approach for designing unit hydrographs in ungauged catchments. The process involved evaluating the integrated similarity between pairs of gauged-ungauged catchments using hydrologic and physical property parameters. This led to the selection of the donor or gauged catchment with the highest similarity score to develop the unit hydrograph for the ungauged catchments. The developed UHs were further applied to estimate the reservoir inflow for the December 25, 2007, flood event. The results showed that the computed peak discharge was 10.9% lower than a previous study. Subsequently, the HEC-HMS simulation model was used to project the updated design flood hydrographs to the reservoir. The design rainfall was derived from automatic rainfall recorder (ARR) and PERSIANN satellite-based data. The ARR data showed that the extreme rainfall duration was 5 hours while satellite data indicated 6 hours. The application of the ARR 5-hour duration to the updated flood hydrographs led to a peak discharge of 5123 m3 s-1, 7041 m3 s-1, and 10,370 m3 s-1 for the 60-year, 500-year, and PMF floods respectively in line with the flood design criteria of Wonogiri Reservoir. These estimates were observed to be significantly higher than the 1982 design floods which were 4000 m3 s-1, 5100 m3 s-1, and 9600 m3 s-1 respectively. This updated flood control design was important to renew the operation rule of the Wonogiri reservoir during flood periods.
{"title":"The Development of Ungauged-Catchment Integrated-Similarity Unit Hydrograph to Estimate Inflow of Wonogiri Reservoir","authors":"Kurniawan Putra, Istiarto Santoso, Rachmad Jayadi","doi":"10.22146/jcef.7051","DOIUrl":"https://doi.org/10.22146/jcef.7051","url":null,"abstract":"The Wonogiri Reservoir is a multipurpose reservoir at the Upper Bengawan Solo Watershed, primarily designed to serve as a flood control system. However, there is no accurate estimation of the inflow into the reservoir due to the limited availability of hydrological stations. Observations showed only four out of ten unit hydrographs of the Wonogiri Reservoir watershed. Therefore, this study was conducted to apply an integrated similarity-based approach for designing unit hydrographs in ungauged catchments. The process involved evaluating the integrated similarity between pairs of gauged-ungauged catchments using hydrologic and physical property parameters. This led to the selection of the donor or gauged catchment with the highest similarity score to develop the unit hydrograph for the ungauged catchments. The developed UHs were further applied to estimate the reservoir inflow for the December 25, 2007, flood event. The results showed that the computed peak discharge was 10.9% lower than a previous study. Subsequently, the HEC-HMS simulation model was used to project the updated design flood hydrographs to the reservoir. The design rainfall was derived from automatic rainfall recorder (ARR) and PERSIANN satellite-based data. The ARR data showed that the extreme rainfall duration was 5 hours while satellite data indicated 6 hours. The application of the ARR 5-hour duration to the updated flood hydrographs led to a peak discharge of 5123 m3 s-1, 7041 m3 s-1, and 10,370 m3 s-1 for the 60-year, 500-year, and PMF floods respectively in line with the flood design criteria of Wonogiri Reservoir. These estimates were observed to be significantly higher than the 1982 design floods which were 4000 m3 s-1, 5100 m3 s-1, and 9600 m3 s-1 respectively. This updated flood control design was important to renew the operation rule of the Wonogiri reservoir during flood periods.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355730","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}
About 3.1 million people use the water from Progo River for domestic use, agriculture, livestock and even for religious rituals which solidifies the importance of Progo River to the residence. However, the characteristics of the Progo River has not been studied well. This paper aims to understand the characteristics of the Progo River and the main threat to the river. To achieve those objectives, a SWOT analysis was used particularly in three segments of Progo River Basin, which is upstream, midstream, and downstream reach. The upstream segment has a basin slope more than 25%, the middle segment has a basin slope of 8-25%, and the downsteam segment has a basin slope less than 8%. The SWOT analysis would be based on desk study, hydrological analysis, water quality analysis and field observation. The upstream segment is characterized by high land erosion rate, steep slope, and the presence of Umbul Jumprit, a holy site for Buddhism. The midstream segment is very close to the residence area which reduces the water quality of the river. Furthermore, some scouring issues and flooding risk have become the main concern in this area. The downstream segment is crossed by several bridges of national roads while also having a gravel mining activity. This activity causes a massive scouring problem to the structures. It is clear that the main threat to the Progo River Basin is volcanic and human activities. For a starter, the government should prioritize the revitalization act in the upstream area which has a great impact on the midstream and downstream areas. Because SWOT analysis from water resources management perspective have never been done in the Progo River Basin, these findings can be served as a foundation for the integrated water resources management in the basin.
{"title":"Water Resources Management in Progo River Basin using SWOT Analysis","authors":"Neil Andika, Ni Made Candra Partarini","doi":"10.22146/jcef.7652","DOIUrl":"https://doi.org/10.22146/jcef.7652","url":null,"abstract":"About 3.1 million people use the water from Progo River for domestic use, agriculture, livestock and even for religious rituals which solidifies the importance of Progo River to the residence. However, the characteristics of the Progo River has not been studied well. This paper aims to understand the characteristics of the Progo River and the main threat to the river. To achieve those objectives, a SWOT analysis was used particularly in three segments of Progo River Basin, which is upstream, midstream, and downstream reach. The upstream segment has a basin slope more than 25%, the middle segment has a basin slope of 8-25%, and the downsteam segment has a basin slope less than 8%. The SWOT analysis would be based on desk study, hydrological analysis, water quality analysis and field observation. The upstream segment is characterized by high land erosion rate, steep slope, and the presence of Umbul Jumprit, a holy site for Buddhism. The midstream segment is very close to the residence area which reduces the water quality of the river. Furthermore, some scouring issues and flooding risk have become the main concern in this area. The downstream segment is crossed by several bridges of national roads while also having a gravel mining activity. This activity causes a massive scouring problem to the structures. It is clear that the main threat to the Progo River Basin is volcanic and human activities. For a starter, the government should prioritize the revitalization act in the upstream area which has a great impact on the midstream and downstream areas. Because SWOT analysis from water resources management perspective have never been done in the Progo River Basin, these findings can be served as a foundation for the integrated water resources management in the basin.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355884","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 global increase in infrastructure development has led to potential shortages of river sand and tap water, particularly in coastal areas, posing challenges for concrete production. To address this issue, numerous studies have been conducted on the use of seawater and sea sand as sustainable alternatives. Rice Husks Ash (RHA), a fine powder derived from the combustion process of agricultural husks, has emerged as potential eco-friendly solution due to its excellent pozzolanic properties, making it a viable candidate for partially replacing cement in concrete. This substitution enhances concrete durability and strength as well as reduces the risk of corrosion in harsh environmental conditions. Therefore, this study examined impact of seawater for mixing, sea sand and substitution ratio of RHA on corrosion of reinforcing bars. The specimen used in the experiment had a thickness of 150 mm, with rectangular areas of 400 x 400 mm and plain steel bars with a diameter of 10 mm. Corrosion levels and concrete quality were evaluated using the half-cell potential (HCP) method and hammer test, respectively. The results showed that all specimens mixed with seawater, river sand, and different substitution ratios of RHA (0%, 5%, 10%, and 15%) exhibited corrosion, as confirmed by the HCP method. However, only the specimen mixed with tap water, sea sand, and an addition of 5% RHA demonstrated effective resistance to corrosion, comparable to normal concrete.
{"title":"The Impact of using Rice Husks Ash, Seawater and Sea Sand on Corrosion of Reinforcing Bars in Concrete","authors":"D. Patah, A. Dasar","doi":"10.22146/jcef.6016","DOIUrl":"https://doi.org/10.22146/jcef.6016","url":null,"abstract":"The global increase in infrastructure development has led to potential shortages of river sand and tap water, particularly in coastal areas, posing challenges for concrete production. To address this issue, numerous studies have been conducted on the use of seawater and sea sand as sustainable alternatives. Rice Husks Ash (RHA), a fine powder derived from the combustion process of agricultural husks, has emerged as potential eco-friendly solution due to its excellent pozzolanic properties, making it a viable candidate for partially replacing cement in concrete. This substitution enhances concrete durability and strength as well as reduces the risk of corrosion in harsh environmental conditions. Therefore, this study examined impact of seawater for mixing, sea sand and substitution ratio of RHA on corrosion of reinforcing bars. The specimen used in the experiment had a thickness of 150 mm, with rectangular areas of 400 x 400 mm and plain steel bars with a diameter of 10 mm. Corrosion levels and concrete quality were evaluated using the half-cell potential (HCP) method and hammer test, respectively. The results showed that all specimens mixed with seawater, river sand, and different substitution ratios of RHA (0%, 5%, 10%, and 15%) exhibited corrosion, as confirmed by the HCP method. However, only the specimen mixed with tap water, sea sand, and an addition of 5% RHA demonstrated effective resistance to corrosion, comparable to normal concrete.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355629","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}
Material movement is a significant and costly aspect of gold or general mining projects. This involves the utilization of expensive heavy equipment, necessitating careful management to ensure optimal efficiency. Therefore, this study aimed to analyze the productivity of excavators PC-300 and PC-400 as well as compare theoretical calculation results with actual conditions. The basis was formed by real field data, collected by earthwork supervisors at a gold mine in Indonesia. This data encompassed daily heavy equipment usage, including the duration, the quantity of material moved, and the types of material involved in the relocation process. The calculations resulted in theoretical productivity of 121.45 m3 hour-1 and 99.56 m3 hour-1 for PC-400 and PC-300. Meanwhile, the calculations based on actual conditions resulted in an average productivity of 114.4 m3 hour-1 and 66.3 m3 hour-1 for PC-400 and PC-300 during a one-year project period. The difference between actual and theoretical productivity for PC-400 and PC-300 was relatively small and large at -7.05 m3 hour-1 and -33.26 m3 hour-1, with 0.94 and 0.64 match factors, respectively. The large difference in productivity for the PC-300 was because the equipment supported work projects, such as opening work area access, maintaining area of work, and serving as supporting equipment. Furthermore, it occurred in the total actual production of the material movement against the one-year target production, which was less than -31,921 m3 (-2.5%) out of the 1,277,325 m3 total. The production deficit was attributed to a construction failure that caused PC-400 and PC-300 to be temporarily relocated for reparation. Based on the simulation, target production was achieved by the actual condition at month 13 (additional 1-month duration) with a total production of 1,283,856 m3, which obtained more than +6,531 m3 (+0.51%).
{"title":"Productivity Analysis PC-300 and PC-400 in Earthworks at a Gold Mining Project in Indonesia","authors":"Muhammad Fahmi, T. Ghuzdewan","doi":"10.22146/jcef.6600","DOIUrl":"https://doi.org/10.22146/jcef.6600","url":null,"abstract":"Material movement is a significant and costly aspect of gold or general mining projects. This involves the utilization of expensive heavy equipment, necessitating careful management to ensure optimal efficiency. Therefore, this study aimed to analyze the productivity of excavators PC-300 and PC-400 as well as compare theoretical calculation results with actual conditions. The basis was formed by real field data, collected by earthwork supervisors at a gold mine in Indonesia. This data encompassed daily heavy equipment usage, including the duration, the quantity of material moved, and the types of material involved in the relocation process. The calculations resulted in theoretical productivity of 121.45 m3 hour-1 and 99.56 m3 hour-1 for PC-400 and PC-300. Meanwhile, the calculations based on actual conditions resulted in an average productivity of 114.4 m3 hour-1 and 66.3 m3 hour-1 for PC-400 and PC-300 during a one-year project period. The difference between actual and theoretical productivity for PC-400 and PC-300 was relatively small and large at -7.05 m3 hour-1 and -33.26 m3 hour-1, with 0.94 and 0.64 match factors, respectively. The large difference in productivity for the PC-300 was because the equipment supported work projects, such as opening work area access, maintaining area of work, and serving as supporting equipment. Furthermore, it occurred in the total actual production of the material movement against the one-year target production, which was less than -31,921 m3 (-2.5%) out of the 1,277,325 m3 total. The production deficit was attributed to a construction failure that caused PC-400 and PC-300 to be temporarily relocated for reparation. Based on the simulation, target production was achieved by the actual condition at month 13 (additional 1-month duration) with a total production of 1,283,856 m3, which obtained more than +6,531 m3 (+0.51%).","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355621","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}
Athena Hastomo, E. Anggraheni, Adi Prasetyo, D. Sutjiningsih, M. A. Pratama, Atina Umi Kalsum
Jakarta is prone to pluvial, fluvial, and coastal flooding due to its geographical location and topography. In response to this problem, the Indonesian government has implemented several master plans, including the National Capital Integrated Coastal Development (NCICD). This ongoing program encompasses the construction of coastal and river embankment that stretch all over the coast of Jakarta. Since many coastal areas in Jakarta are residential or industrial, evaluating this performance of embankment has become crucial for effective flood management. The findings of this research can also support the development of other locations where NCICD embankment plan and enhance coastal resilience. Therefore, this research assessed the effectiveness of coastal and river embankment at Cengkareng Drain, a vital floodway in Jakarta, during extreme events that occur simultaneously. To simulate flooding events, two-dimensional HEC-RAS features were used to numerically calculate the area and depth of inundation. The simulation required geometry, terrain, land cover, and unsteady flow data. For the flow boundary conditions, a 100-year design rainfall, HHWL (Highest High Water Level), and 100-year design wave were considered to represent estuary conditions accurately. The simulation result showed that the maximum water level influenced by these factors was +3.145 mMSL, while the planned embankment top elevation was +3.40 mMSL. Furthermore, without the NCICD embankment, the simulation showed an inundation area of 1212.37 ha, which was reduced to 1111.22 ha after their implementation, leading to a decrease of 101.15 ha. This reduction significantly decreases potential damage to property and infrastructure, particularly in densely populated areas. The simulation also showed a reduction of 86.49 hectares or 66.22% in the inundation area with a depth exceeding 1 meter. These findings demonstrate the effectiveness of embankment in reducing the inundation area without any overtopping incidents.
{"title":"Coastal and River Embankment Performance at Cengkareng Drain Estuary Under Compound Hazards Conditions Using HEC-RAS 2D","authors":"Athena Hastomo, E. Anggraheni, Adi Prasetyo, D. Sutjiningsih, M. A. Pratama, Atina Umi Kalsum","doi":"10.22146/jcef.7087","DOIUrl":"https://doi.org/10.22146/jcef.7087","url":null,"abstract":"Jakarta is prone to pluvial, fluvial, and coastal flooding due to its geographical location and topography. In response to this problem, the Indonesian government has implemented several master plans, including the National Capital Integrated Coastal Development (NCICD). This ongoing program encompasses the construction of coastal and river embankment that stretch all over the coast of Jakarta. Since many coastal areas in Jakarta are residential or industrial, evaluating this performance of embankment has become crucial for effective flood management. The findings of this research can also support the development of other locations where NCICD embankment plan and enhance coastal resilience. Therefore, this research assessed the effectiveness of coastal and river embankment at Cengkareng Drain, a vital floodway in Jakarta, during extreme events that occur simultaneously. To simulate flooding events, two-dimensional HEC-RAS features were used to numerically calculate the area and depth of inundation. The simulation required geometry, terrain, land cover, and unsteady flow data. For the flow boundary conditions, a 100-year design rainfall, HHWL (Highest High Water Level), and 100-year design wave were considered to represent estuary conditions accurately. The simulation result showed that the maximum water level influenced by these factors was +3.145 mMSL, while the planned embankment top elevation was +3.40 mMSL. Furthermore, without the NCICD embankment, the simulation showed an inundation area of 1212.37 ha, which was reduced to 1111.22 ha after their implementation, leading to a decrease of 101.15 ha. This reduction significantly decreases potential damage to property and infrastructure, particularly in densely populated areas. The simulation also showed a reduction of 86.49 hectares or 66.22% in the inundation area with a depth exceeding 1 meter. These findings demonstrate the effectiveness of embankment in reducing the inundation area without any overtopping incidents.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355735","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}
A low-to-medium cohesionless soil with low fines content was predominantly observed at the surfaces of Yogyakarta International Airport (YIA). The condition exposed subsoil of YIA to Liquefaction in addition to its location on a high seismic zone which has increased the likelihood of massive ground shaking. This means it is necessary to improve soil condition and vibro-replacement using stone column was selected as the appropriate method due to its recent popularity for the enhancement of sandy ground. Stone column has the ability to reduce the Cyclic Stress Ratio (CSR) of liquefiable soil and can be reliably evaluated. Therefore, this study was conducted to evaluate the risk of Liquefaction at YIA by adopting the SPT-based Liquefaction triggering procedure and presuming its manifestation using Liquefaction Severity Index (LSI). It is pertinent to state that the theoretical approach introduced by Priebe was used to design the geometry and center-to-center distance of stone column. The results were presented in the form of maps with a 50 m × 50 m grid size which include the cut and fill, LSI before and after improvement, stone column spacing, as well as stone column depth. It was discovered that the triangular spacing required for stone column ranged from 1.25 m to 2.5 m while the maximum depth was found to be 6 m. Moreover, stone column inclusion efficiently reduced the severity of Liquefaction from medium to very low for the areas studied. However, stone column has several limitations and this means a combination of soil improvement methods needs to be applied to areas with moderate LSI.
在日惹国际机场(YIA)表面主要观察到低颗粒含量的低至中等粘性土。这种情况使YIA的底土暴露于液化，而且它位于高地震带，这增加了大规模地面震动的可能性。这意味着改善土壤条件是必要的，采用石柱振动置换法加固沙质地基是目前比较流行的方法。石柱具有降低可液化土循环应力比的能力，可以可靠地进行评估。因此，本研究采用基于spt的液化触发程序，并使用液化严重程度指数(LSI)假设其表现形式，对YIA的液化风险进行评估。需要指出的是，我们采用了Priebe引入的理论方法来设计石柱的几何形状和中心到中心的距离。结果以50 m × 50 m网格尺寸的图的形式呈现，其中包括切割和填充，改进前后的LSI，石柱间距以及石柱深度。发现石柱所需的三角形间距为1.25 m ~ 2.5 m，最大深度为6 m。此外，石柱包裹体有效地将所研究地区的液化严重程度从中等降低到极低。然而，石柱有一些局限性，这意味着土壤改良方法的组合需要应用于中等大规模集成电路的地区。
{"title":"Design of Stone Column to Mitigate Soil Liquefaction: Cases Study of Yogyakarta International Airport","authors":"Nicholas Hartono, T. Fathani","doi":"10.22146/jcef.5933","DOIUrl":"https://doi.org/10.22146/jcef.5933","url":null,"abstract":"A low-to-medium cohesionless soil with low fines content was predominantly observed at the surfaces of Yogyakarta International Airport (YIA). The condition exposed subsoil of YIA to Liquefaction in addition to its location on a high seismic zone which has increased the likelihood of massive ground shaking. This means it is necessary to improve soil condition and vibro-replacement using stone column was selected as the appropriate method due to its recent popularity for the enhancement of sandy ground. Stone column has the ability to reduce the Cyclic Stress Ratio (CSR) of liquefiable soil and can be reliably evaluated. Therefore, this study was conducted to evaluate the risk of Liquefaction at YIA by adopting the SPT-based Liquefaction triggering procedure and presuming its manifestation using Liquefaction Severity Index (LSI). It is pertinent to state that the theoretical approach introduced by Priebe was used to design the geometry and center-to-center distance of stone column. The results were presented in the form of maps with a 50 m × 50 m grid size which include the cut and fill, LSI before and after improvement, stone column spacing, as well as stone column depth. It was discovered that the triangular spacing required for stone column ranged from 1.25 m to 2.5 m while the maximum depth was found to be 6 m. Moreover, stone column inclusion efficiently reduced the severity of Liquefaction from medium to very low for the areas studied. However, stone column has several limitations and this means a combination of soil improvement methods needs to be applied to areas with moderate LSI.","PeriodicalId":31890,"journal":{"name":"Journal of the Civil Engineering Forum","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77904124","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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