Monitoring floods using optical satellite images in winter is challenging. Because of the thickness of clouds, the electromagnetic bands used by satellites are too narrow and the resulting signals are reflected into space. The purpose of this study is to assess the potential of implementing a high-resolution synthetic aperture radar system (SAR) for the purpose of mapping floods in Jordan while the weather is cloudy. TerraSAR-X satellite was utilized to acquire images of high resolution for flood monitoring. This research employed TerraSAR-X thresholding images to identify flood-prone areas and track floods over time using time-series images. It was possible to determine the places of the landscape that have been impacted by the flood and to establish the degree of damage by conducting an analysis of the changes that have occurred in the landscape. The accuracy of the study's findings was confirmed using backscatter texture analysis on the images, which revealed a small difference between thresholding and texture analysis approaches of less than 3% in the mapped test region's flood area. While monitoring floods, it is recommended to use TerraSAR-X images, particularly in conjunction with other data sources, such as weather predictions and hydrological models. KEYWORDS: Flood mapping, Polarimetric SAR, TerraSAR-X, Texture analysis, Thresholding, Interferometric SAR
{"title":"Mapping Floods during Cloudy Weather Using Radar Satellite Images","authors":"Nawras Shatnawi","doi":"10.14525/jjce.v18i1.03","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.03","url":null,"abstract":"Monitoring floods using optical satellite images in winter is challenging. Because of the thickness of clouds, the electromagnetic bands used by satellites are too narrow and the resulting signals are reflected into space. The purpose of this study is to assess the potential of implementing a high-resolution synthetic aperture radar system (SAR) for the purpose of mapping floods in Jordan while the weather is cloudy. TerraSAR-X satellite was utilized to acquire images of high resolution for flood monitoring. This research employed TerraSAR-X thresholding images to identify flood-prone areas and track floods over time using time-series images. It was possible to determine the places of the landscape that have been impacted by the flood and to establish the degree of damage by conducting an analysis of the changes that have occurred in the landscape. The accuracy of the study's findings was confirmed using backscatter texture analysis on the images, which revealed a small difference between thresholding and texture analysis approaches of less than 3% in the mapped test region's flood area. While monitoring floods, it is recommended to use TerraSAR-X images, particularly in conjunction with other data sources, such as weather predictions and hydrological models. KEYWORDS: Flood mapping, Polarimetric SAR, TerraSAR-X, Texture analysis, Thresholding, Interferometric SAR","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":" 698","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139391812","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}
One of the geotechnical-engineering roles is soil stabilization, because it affects the long-term strength and functionality of structures. For suitability and durability of expansive soils for construction projects, shear strength, bearing capacity and other characteristics can be enhanced through the stabilization process. This study is focused on the effects of steel factory dust (SFD) as an additive on the improvement of the undesired geotechnical properties of expansive soil (CH soil). A series of laboratory tests were conducted on intact and treated samples. SFD was added by 0, 2, 4, 6, 8 and 10% to the dry soil. The conducted tests are consistency, specific-gravity, modified Proctor compaction, swelling-pressure and -percent and unconfined compression tests. The addition of SFD reduced the values of liquid and plastic limits, plasticity index, modulus of elasticity and allowable bearing capacity. Significantly, the 10% SFD addition significantly reduced swelling percent and pressure by 26.8% and 25.4%, respectively while notably increasing the unconfined compressive strength (UCS) from 475 MPa to 629 MPa. SFD was found to be a successful waste material in improving expansive soil by using 10% as the best addition percent, which usefully saves the environment. KEYWORDS: Expansive soil, Stabilization, Steel factory dust, Swelling, Unconfined compressive strength. INTRODUCTIO
{"title":"Expansive Soil Stabilization Using Steel Factory Dust","authors":"Z. Abdalqadir","doi":"10.14525/jjce.v18i1.11","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.11","url":null,"abstract":"One of the geotechnical-engineering roles is soil stabilization, because it affects the long-term strength and functionality of structures. For suitability and durability of expansive soils for construction projects, shear strength, bearing capacity and other characteristics can be enhanced through the stabilization process. This study is focused on the effects of steel factory dust (SFD) as an additive on the improvement of the undesired geotechnical properties of expansive soil (CH soil). A series of laboratory tests were conducted on intact and treated samples. SFD was added by 0, 2, 4, 6, 8 and 10% to the dry soil. The conducted tests are consistency, specific-gravity, modified Proctor compaction, swelling-pressure and -percent and unconfined compression tests. The addition of SFD reduced the values of liquid and plastic limits, plasticity index, modulus of elasticity and allowable bearing capacity. Significantly, the 10% SFD addition significantly reduced swelling percent and pressure by 26.8% and 25.4%, respectively while notably increasing the unconfined compressive strength (UCS) from 475 MPa to 629 MPa. SFD was found to be a successful waste material in improving expansive soil by using 10% as the best addition percent, which usefully saves the environment. KEYWORDS: Expansive soil, Stabilization, Steel factory dust, Swelling, Unconfined compressive strength. INTRODUCTIO","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":"47 32","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139394868","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 paper aims to explore the tensile properties of plant fiber-reinforced cementitious composites (PFRCCs). An axial tensile numerical-simulation and test study of PFRCC panels with four thicknesses was performed to analyze their tensile properties, providing a relevant basis for the engineering application of PFRCC panels. The results show that the peak load of uniaxial tensile failure of PFRCC panels with thicknesses of 8 mm, 12 mm, 15 mm and 18 mm is 424.0 N, 664.8 N, 825.0 N and 986.4 N, respectively. The bearing capacity of the panels gradually increases with the increase of the thickness. The peak tensile strain is about 0.044%, 2.93 times that of the cement matrix and the tensile strength is about 2.73 MPa. It is proved that adding plant fiber can increase the toughness of the cement matrix and increasing PFRCC panel thickness can improve its tensile bearing capacity without affecting its tensile-strength. KEYWORDS: Composite materials, Cement matrix, Plant fiber, Axial tension.
{"title":"Study On Axial Stretching Mechanical Property Of Plant Fiber Reinforced Cementitious Composites","authors":"Xinyuan Wang","doi":"10.14525/jjce.v18i1.05","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.05","url":null,"abstract":"This paper aims to explore the tensile properties of plant fiber-reinforced cementitious composites (PFRCCs). An axial tensile numerical-simulation and test study of PFRCC panels with four thicknesses was performed to analyze their tensile properties, providing a relevant basis for the engineering application of PFRCC panels. The results show that the peak load of uniaxial tensile failure of PFRCC panels with thicknesses of 8 mm, 12 mm, 15 mm and 18 mm is 424.0 N, 664.8 N, 825.0 N and 986.4 N, respectively. The bearing capacity of the panels gradually increases with the increase of the thickness. The peak tensile strain is about 0.044%, 2.93 times that of the cement matrix and the tensile strength is about 2.73 MPa. It is proved that adding plant fiber can increase the toughness of the cement matrix and increasing PFRCC panel thickness can improve its tensile bearing capacity without affecting its tensile-strength. KEYWORDS: Composite materials, Cement matrix, Plant fiber, Axial tension.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":"30 30","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139394053","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 paper presents two hybrid optimization methods known as PSOHHO and DPSOHHO optimization algorithms. In the first method, using a number of formulae, the top populations are exchanged between the two algorithms and a new population is created and in the second method, we adopted the parallel optimization and optimized its performance. In this method, unlike other parallel methods, the population does not remain constant. With this ability, the strengths of an algorithm can be used to compensate for the weaknesses of the other algorithm. In these methods, no changes are made to the algorithms. The main goal is to use existing algorithms. These methods attain the optimal solution in the shortest time possible. Two algorithms of particleswarm optimization (PSO) and Harris Hawks's optimization (HHO) are used to present this method and two truss samples and CEC209 are considered to confirm the performance of this method. Based on the results, these methods have rapid convergence speed and acceptable results compared to other methods. KEYWORDS: Meta-heuristic algorithms, Hybrid algorithm, Optimization, Dynamic hybrid algorithm, Truss.
{"title":"Optimal Design of Truss Using a Hybrid Method Based on Particle Swarm Optimizer and Harris Hawk Algorithm","authors":"M. Yassami","doi":"10.14525/jjce.v18i1.07","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.07","url":null,"abstract":"This paper presents two hybrid optimization methods known as PSOHHO and DPSOHHO optimization algorithms. In the first method, using a number of formulae, the top populations are exchanged between the two algorithms and a new population is created and in the second method, we adopted the parallel optimization and optimized its performance. In this method, unlike other parallel methods, the population does not remain constant. With this ability, the strengths of an algorithm can be used to compensate for the weaknesses of the other algorithm. In these methods, no changes are made to the algorithms. The main goal is to use existing algorithms. These methods attain the optimal solution in the shortest time possible. Two algorithms of particleswarm optimization (PSO) and Harris Hawks's optimization (HHO) are used to present this method and two truss samples and CEC209 are considered to confirm the performance of this method. Based on the results, these methods have rapid convergence speed and acceptable results compared to other methods. KEYWORDS: Meta-heuristic algorithms, Hybrid algorithm, Optimization, Dynamic hybrid algorithm, Truss.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":"44 10","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139395393","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 study aimed to evaluate the accident-causing factors affecting the total cost of building construction projects using a structural-equation model (SEM). Through the analysis of 35 identified factors categorized into construction, natural disaster, physical and human and psychological domains, this study examined their effects on project costs. The data collected from 120 construction experts in Iraq was analyzed using the SmartPLS software. This study assessed the fit of the measurement model using the following key criteria: reliability, convergent validity and divergent validity. All latent constructs demonstrated Cronbach’s-alpha values of above 0.70 and composite-reliability (CR) values of above 0.70, indicating their reliability. The average variance extracted (AVE) values exceeded the 0.5 threshold, confirming convergent validity. The model also demonstrated acceptable discriminant validity. The results confirmed the significant impact of accident-causing factors on project costs, with "excessive physical activity," "storm," "improper ventilation," "low motivation and low efficiency of the workers," and "fire, explosion and vibration" emerging as the top five influencing factors. These findings emphasized the need for tailored safety measures to mitigate such risks. The study underscored the importance of addressing accident-causing factors to enhance both safety planning and financial outcomes in building construction projects. KEYWORDS: Accident-causing factors, Project cost, Construction-project management, Safety assessment, Structural-equation modeling
{"title":"Assessing the Accident-Cost Relationship in Building Construction Projects Using Structural Equation Modeling","authors":"Milad Ghanbari","doi":"10.14525/jjce.v18i1.02","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.02","url":null,"abstract":"This study aimed to evaluate the accident-causing factors affecting the total cost of building construction projects using a structural-equation model (SEM). Through the analysis of 35 identified factors categorized into construction, natural disaster, physical and human and psychological domains, this study examined their effects on project costs. The data collected from 120 construction experts in Iraq was analyzed using the SmartPLS software. This study assessed the fit of the measurement model using the following key criteria: reliability, convergent validity and divergent validity. All latent constructs demonstrated Cronbach’s-alpha values of above 0.70 and composite-reliability (CR) values of above 0.70, indicating their reliability. The average variance extracted (AVE) values exceeded the 0.5 threshold, confirming convergent validity. The model also demonstrated acceptable discriminant validity. The results confirmed the significant impact of accident-causing factors on project costs, with \"excessive physical activity,\" \"storm,\" \"improper ventilation,\" \"low motivation and low efficiency of the workers,\" and \"fire, explosion and vibration\" emerging as the top five influencing factors. These findings emphasized the need for tailored safety measures to mitigate such risks. The study underscored the importance of addressing accident-causing factors to enhance both safety planning and financial outcomes in building construction projects. KEYWORDS: Accident-causing factors, Project cost, Construction-project management, Safety assessment, Structural-equation modeling","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":" 26","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139391939","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 investigated the utilization of palm oil waste as a source material for developing an alkaliactivated binder with alumina-silicate properties. The geopolymer synthesis involved a combination of palm oil fuel ash (POFA) and fly ash (FA), as well as sodium silicate and sodium hydroxide as alkali activator solutions. The study assessed the physical, mechanical, water-transport and thermal performances of the binder, including the influence of oxide ratios on its strength-gain characteristic. The highest strength achieved was 54.7 MPa for a blend of POFA-FA in a ratio of 20:50 with a molarity of NaOH at 12M. The experimental results revealed good water-transport performance due to the dense nature of the binder that restricted water movement. However, the material's insulation performance did not produce significant results with the lowest thermal conductivity value of 0.59 W/mK. Overall, the developed binder has potential industrial applications, as it performed well in the technical aspects studied. KEYWORDS: Palm oil fuel ash, Alkali-activated binder, Waste, Sustainability, Water-transport performance.
{"title":"Using Palm Oil Fuel Ash as a Source Material for Alumina Silicate","authors":"Rehaman Dudekula","doi":"10.14525/jjce.v18i1.09","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.09","url":null,"abstract":"This research investigated the utilization of palm oil waste as a source material for developing an alkaliactivated binder with alumina-silicate properties. The geopolymer synthesis involved a combination of palm oil fuel ash (POFA) and fly ash (FA), as well as sodium silicate and sodium hydroxide as alkali activator solutions. The study assessed the physical, mechanical, water-transport and thermal performances of the binder, including the influence of oxide ratios on its strength-gain characteristic. The highest strength achieved was 54.7 MPa for a blend of POFA-FA in a ratio of 20:50 with a molarity of NaOH at 12M. The experimental results revealed good water-transport performance due to the dense nature of the binder that restricted water movement. However, the material's insulation performance did not produce significant results with the lowest thermal conductivity value of 0.59 W/mK. Overall, the developed binder has potential industrial applications, as it performed well in the technical aspects studied. KEYWORDS: Palm oil fuel ash, Alkali-activated binder, Waste, Sustainability, Water-transport performance.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":" 12","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139393198","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}
One of the challenges in using Manning’s equation lies in accurately determining Manning’s roughness coefficient, especially due to sediment transport. The condition of sediment transport within a specific section of a river can be in equilibrium, meaning that the amount of sediment entering and exiting the segment is balanced or it can be in non-equilibrium, where there is an imbalance between the sediment entering and leaving the segment. Experiments were carried out in the laboratory to simulate both transport conditions, one involving sediment feeding (equilibrium condition) and the other without sediment feeding (non-equilibrium condition). A total of 180 mean velocity profiles were measured using an acoustic doppler velocimeter (ADV) in fixed and movable bed flows. The present experiment was combined with theoretical approaches to evaluate Manning’s coefficient in open channels under sediment transport-flow conditions and reach conclusive results. The shape of the velocity profile, u/U, for flows over a movable bed with sediment feeding is “slender” compared to those without sediment feeding. The presence of sediment transport affects the shape of the velocity profile, especially in the inner region, influencing Manning's roughness coefficient. This coefficient can be determined from two-point velocity measurements at z/H = 0.1 and 0.2 for fixed and movable bed flows with and without sediment feeding, respectively. On average, sediment feeding increases the coefficient by 19% compared to the non-sediment feeding case. KEYWORDS: Manning’s roughness coefficient, Velocity profile, Equilibrium and non-equilibrium, Sediment transport, Open-channel flow
{"title":"Evaluating Manning's Roughness Coefficient for Flows with Equilibrium and Non-equilibrium Sediment Transport","authors":"Miskar Maini","doi":"10.14525/jjce.v18i1.06","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.06","url":null,"abstract":"One of the challenges in using Manning’s equation lies in accurately determining Manning’s roughness coefficient, especially due to sediment transport. The condition of sediment transport within a specific section of a river can be in equilibrium, meaning that the amount of sediment entering and exiting the segment is balanced or it can be in non-equilibrium, where there is an imbalance between the sediment entering and leaving the segment. Experiments were carried out in the laboratory to simulate both transport conditions, one involving sediment feeding (equilibrium condition) and the other without sediment feeding (non-equilibrium condition). A total of 180 mean velocity profiles were measured using an acoustic doppler velocimeter (ADV) in fixed and movable bed flows. The present experiment was combined with theoretical approaches to evaluate Manning’s coefficient in open channels under sediment transport-flow conditions and reach conclusive results. The shape of the velocity profile, u/U, for flows over a movable bed with sediment feeding is “slender” compared to those without sediment feeding. The presence of sediment transport affects the shape of the velocity profile, especially in the inner region, influencing Manning's roughness coefficient. This coefficient can be determined from two-point velocity measurements at z/H = 0.1 and 0.2 for fixed and movable bed flows with and without sediment feeding, respectively. On average, sediment feeding increases the coefficient by 19% compared to the non-sediment feeding case. KEYWORDS: Manning’s roughness coefficient, Velocity profile, Equilibrium and non-equilibrium, Sediment transport, Open-channel flow","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":"30 5","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139394598","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 behaviour of two-way reinforced-concrete slabs exposed to direct fire was investigated in this study. The slabs were exposed to fire for one hour in a gas furnace and the flame-spread area was varied by increasing the number of fire sources from three to six. The slabs were cooled in two different ways: gradual cooling and sudden cooling. The results showed that the flame-spread area had a significant effect on the load-carrying capacity and deflection of the slabs. The load-carrying capacity decreased by 20.68% with gradual cooling and by 33.78% with sudden cooling when the flame-spread area was increased. The deflection at failure increased by 26.3% with gradual cooling and by 33.78% with sudden cooling when the flame-spread area was increased. The ductility factor showed an increase of 12.6% to 50.3 % for gradually-cooled slabs and of 50.3% to 59.6% for suddenly-cooled slabs with an increasing flame-spread area, compared to reference slabs. KEYWORDS: Reinforced solid concrete slabs, Direct fire flame, Thermal flame, Cooling method.
{"title":"Fire Performance of Reinforced Concrete Slabs: Direct Flame Effects","authors":"Raneen Aldarf","doi":"10.14525/jjce.v18i1.08","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.08","url":null,"abstract":"The behaviour of two-way reinforced-concrete slabs exposed to direct fire was investigated in this study. The slabs were exposed to fire for one hour in a gas furnace and the flame-spread area was varied by increasing the number of fire sources from three to six. The slabs were cooled in two different ways: gradual cooling and sudden cooling. The results showed that the flame-spread area had a significant effect on the load-carrying capacity and deflection of the slabs. The load-carrying capacity decreased by 20.68% with gradual cooling and by 33.78% with sudden cooling when the flame-spread area was increased. The deflection at failure increased by 26.3% with gradual cooling and by 33.78% with sudden cooling when the flame-spread area was increased. The ductility factor showed an increase of 12.6% to 50.3 % for gradually-cooled slabs and of 50.3% to 59.6% for suddenly-cooled slabs with an increasing flame-spread area, compared to reference slabs. KEYWORDS: Reinforced solid concrete slabs, Direct fire flame, Thermal flame, Cooling method.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":"60 2","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139394720","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}
An unlined rock-blast tunnel constructed by the drill and blast method is susceptible to frequent deterioration, including sagging beds, water ingress and loose rock masses. Thus, assessing potential damages above the roadway that may impact the safety of tunnel users is of utmost importance. While tapping, a conventional nondestructive method, is typically used to predict sub-surface delamination, water ingress can be identified with the naked eye. In this research, we utilized a modern-technology approach called passive thermography, together with a high-resolution digital camera and tapping. The study encountered two primary challenges; namely, the absence of direct solar radiation during the inspection and the groove-exposed surface of the unlined tunnel. The results demonstrated that passive thermography was able to detect delaminated areas and water infiltration on the tunnel's walls and ceiling, even without direct sunlight. Large delaminated areas can be detected with just a 2°C change in atmospheric temperature twelve hours before testing. Additionally, the results of image post-processing significantly contributed to enhancing the results of passive thermography. The thermal image was processed into a grayscale image prior to HE processing, which enhances contrast by over 50%. The combination of tapping, digital camera and passive thermography was proven to be effective in periodically inspecting unlined rock tunnels, while significantly reducing time and cost. KEYWORDS: Tunnel safety, Passive thermography, Old rock-cut tunnel, Hammer sounding, Non-destructive evaluation, Image post-processing.
采用钻爆法建造的无衬砌岩石爆破隧道容易经常出现老化问题，包括路基下陷、进水和岩块松动。因此，评估巷道上方可能影响隧道使用者安全的潜在损坏至关重要。传统的非破坏性方法--敲击法通常用于预测地表下的分层，而进水则可以用肉眼识别。在这项研究中，我们采用了一种名为被动热成像的现代技术方法，同时还使用了高分辨率数码相机和拍击法。这项研究遇到了两个主要挑战：一是检查期间没有太阳直射，二是无衬砌隧道的沟槽表面裸露在外。结果表明，即使没有阳光直射，被动热成像技术也能检测到隧道墙壁和天花板上的脱层区域和渗水情况。在测试前 12 小时，大气温度仅有 2°C 的变化，就能检测到大面积分层区域。此外，图像后处理的结果也大大提高了被动热成像的效果。在 HE 处理之前，热图像被处理成灰度图像，对比度提高了 50% 以上。事实证明，在对无衬砌岩石隧道进行定期检查时，攻丝机、数码相机和被动热成像技术的组合非常有效，同时还大大减少了时间和成本。关键词： 隧道安全、被动热成像仪、旧岩石切割隧道、锤击探测、无损评估、图像后处理。
{"title":"Detection of Sub-surface Delamination and Moisture Penetration in Unlined Rock Tunnels Using Passive Thermography and Tapping","authors":"Jungwon Huh","doi":"10.14525/jjce.v18i1.01","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.01","url":null,"abstract":"An unlined rock-blast tunnel constructed by the drill and blast method is susceptible to frequent deterioration, including sagging beds, water ingress and loose rock masses. Thus, assessing potential damages above the roadway that may impact the safety of tunnel users is of utmost importance. While tapping, a conventional nondestructive method, is typically used to predict sub-surface delamination, water ingress can be identified with the naked eye. In this research, we utilized a modern-technology approach called passive thermography, together with a high-resolution digital camera and tapping. The study encountered two primary challenges; namely, the absence of direct solar radiation during the inspection and the groove-exposed surface of the unlined tunnel. The results demonstrated that passive thermography was able to detect delaminated areas and water infiltration on the tunnel's walls and ceiling, even without direct sunlight. Large delaminated areas can be detected with just a 2°C change in atmospheric temperature twelve hours before testing. Additionally, the results of image post-processing significantly contributed to enhancing the results of passive thermography. The thermal image was processed into a grayscale image prior to HE processing, which enhances contrast by over 50%. The combination of tapping, digital camera and passive thermography was proven to be effective in periodically inspecting unlined rock tunnels, while significantly reducing time and cost. KEYWORDS: Tunnel safety, Passive thermography, Old rock-cut tunnel, Hammer sounding, Non-destructive evaluation, Image post-processing.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":" 26","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139392802","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}
his study was conducted to investigate the effect of strengthening with ferro-cement on the flexural behavior of two-way RC slabs after exposure to direct fire. Twelve reinforced-concrete slabs were exposed to direct fire for one hour and cooled with air and water. They were then rehabilitated with a layer of ferro-cement using different bonding patterns (surface roughening, SBR material and screws). The effect of these variables was studied on the load-deflection relationship, ultimate load capacity, stiffness, energy absorption, ductility factor and strains of the compressed zone. The results showed a significant improvement in all the investigated parameters, demonstrating the efficiency of ferro-cement strengthening in improving the behavior of the slabs. It contributed to increasing the ultimate load capacity and initial stiffness of the slabs and to preventing and arresting crack propagation after cracking and even after reaching collapse. The effectiveness of SBR material in ensuring the bonding between the surface of the damaged slabs and the reinforcement layer was also revealed. KEYWORDS: Solid slab, Direct fire flame, Ferro-cement, Rehabilitation, SBR (styrene-butadiene rubber), Roughing.
{"title":"Rehabilitation of Fire-damaged Reinforced-concrete Slabs Using Ferro-cement","authors":"Raneen Aldarf","doi":"10.14525/jjce.v18i1.10","DOIUrl":"https://doi.org/10.14525/jjce.v18i1.10","url":null,"abstract":"his study was conducted to investigate the effect of strengthening with ferro-cement on the flexural behavior of two-way RC slabs after exposure to direct fire. Twelve reinforced-concrete slabs were exposed to direct fire for one hour and cooled with air and water. They were then rehabilitated with a layer of ferro-cement using different bonding patterns (surface roughening, SBR material and screws). The effect of these variables was studied on the load-deflection relationship, ultimate load capacity, stiffness, energy absorption, ductility factor and strains of the compressed zone. The results showed a significant improvement in all the investigated parameters, demonstrating the efficiency of ferro-cement strengthening in improving the behavior of the slabs. It contributed to increasing the ultimate load capacity and initial stiffness of the slabs and to preventing and arresting crack propagation after cracking and even after reaching collapse. The effectiveness of SBR material in ensuring the bonding between the surface of the damaged slabs and the reinforcement layer was also revealed. KEYWORDS: Solid slab, Direct fire flame, Ferro-cement, Rehabilitation, SBR (styrene-butadiene rubber), Roughing.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":" 8","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139393191","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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