The current research aimed to obtain mean pressure distribution over an air-inflated membrane structure using Computational Wind Engineering tools. The steady-state analysis applied the Reynolds-Averaged Navier-Stokes equations with the standard turbulence model. The pressure coefficients were compared with former experimental results to validate the numerical solution. Significant errors were detected close to the critical flow separation points when comparing the numerical results with the wind tunnel tests. However, these errors are local, and the numerical methodology provides accurate results in those areas with minor turbulence motion influence. In general, the numerical solution provided good approximation of the pressure coefficient fields.
{"title":"Computational wind analysis of an open air-inflated membrane structure","authors":"Sherly Joanna Pool-Blanco, K. Hincz","doi":"10.1556/606.2023.00804","DOIUrl":"https://doi.org/10.1556/606.2023.00804","url":null,"abstract":"The current research aimed to obtain mean pressure distribution over an air-inflated membrane structure using Computational Wind Engineering tools. The steady-state analysis applied the Reynolds-Averaged Navier-Stokes equations with the standard turbulence model. The pressure coefficients were compared with former experimental results to validate the numerical solution. Significant errors were detected close to the critical flow separation points when comparing the numerical results with the wind tunnel tests. However, these errors are local, and the numerical methodology provides accurate results in those areas with minor turbulence motion influence. In general, the numerical solution provided good approximation of the pressure coefficient fields.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45801411","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}
Due to the increase in earthquake activity in Iraq and Middle East during the last two decades, the study and understanding of probable destructive action and the best method to mitigate this effect became more important. So, many improvements and mitigation methods can be used. In this study, the use of permeation grout technique was adopted to prevent the existing soil condition in urban area by using cement kiln dust and bentonite clay. The tests were executed by using 1 g shaking table apparatus to simulate a sinusoidal motion (vibration) at specified different frequencies. The liquefaction phenomena were observed for loose saturated sand at 60 s, 25 s, and 10 s for 0.5 Hz, 0.75 Hz, and 1 Hz, respectively. After mitigation process, the soil liquefaction did not occur until 100 s, 60 s, and 30 s, for the same mentioned frequencies. Besides, the use of cement kiln dust decreases the liquefaction potential and increase the factor of safety.
{"title":"Improvement of liquefaction potential in saturated sandy soil by CKD and bentonite","authors":"Ahmed Sadiq, B. Albusoda, Tawfek Sheer Ali","doi":"10.1556/606.2023.00879","DOIUrl":"https://doi.org/10.1556/606.2023.00879","url":null,"abstract":"Due to the increase in earthquake activity in Iraq and Middle East during the last two decades, the study and understanding of probable destructive action and the best method to mitigate this effect became more important. So, many improvements and mitigation methods can be used. In this study, the use of permeation grout technique was adopted to prevent the existing soil condition in urban area by using cement kiln dust and bentonite clay. The tests were executed by using 1 g shaking table apparatus to simulate a sinusoidal motion (vibration) at specified different frequencies. The liquefaction phenomena were observed for loose saturated sand at 60 s, 25 s, and 10 s for 0.5 Hz, 0.75 Hz, and 1 Hz, respectively. After mitigation process, the soil liquefaction did not occur until 100 s, 60 s, and 30 s, for the same mentioned frequencies. Besides, the use of cement kiln dust decreases the liquefaction potential and increase the factor of safety.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43156602","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}
Side friction refers to combined variables indicating the degree of interaction between the activities and the traffic stream. The condition worsens when the transport demand and road-side activities increase, leading to inefficient traffic performance. This study has been focused on evaluating side friction impacts in terms of capacity and speed. Four links divided and undivided streets in Al-Najaf City, Iraq, were selected and on-street parking, pedestrian activities, entry-exit maneuvers, and temporary parking vehicles are considered as side friction elements. The results show about a 47% reduction in speed and about a 49% reduction in the capacity at a very high side friction level. Finally, a speed-predicting model has been developed for predicting the speed under side friction impacts.
{"title":"Side-friction impacts on urban streets performance in divided and undivided streets","authors":"A. Mansour, H. Al-Jameel","doi":"10.1556/606.2023.00817","DOIUrl":"https://doi.org/10.1556/606.2023.00817","url":null,"abstract":"Side friction refers to combined variables indicating the degree of interaction between the activities and the traffic stream. The condition worsens when the transport demand and road-side activities increase, leading to inefficient traffic performance. This study has been focused on evaluating side friction impacts in terms of capacity and speed. Four links divided and undivided streets in Al-Najaf City, Iraq, were selected and on-street parking, pedestrian activities, entry-exit maneuvers, and temporary parking vehicles are considered as side friction elements. The results show about a 47% reduction in speed and about a 49% reduction in the capacity at a very high side friction level. Finally, a speed-predicting model has been developed for predicting the speed under side friction impacts.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46420401","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}
Musaab A. A. Mohammed, Balázs Kovács, N. Szabó, P. Szűcs
The multi-aquifer system of the Nubian aquifer in central Sudan hydrogeological system was simulated using a three-dimensional steady-state model. The goal of the study is to detect the effect of pumping on the groundwater flow and thus, the aquifer productivity. The conceptual model of the study area was built based on the available geological and hydrogeological data guided by geophysical survey. Processing MODFLOW numerical code was used to calculate the hydraulic head and water balance under the existing boundary conditions. The model accurately simulated the hydraulic head with a determination coefficient of 0.88. The calibrated model indicated that the change in storage is 0.56 m3/day indicating the study area constitutes highly productive zone and is recommended for groundwater developments.
{"title":"Steady-state simulation of groundwater flow in Khartoum state, Sudan","authors":"Musaab A. A. Mohammed, Balázs Kovács, N. Szabó, P. Szűcs","doi":"10.1556/606.2023.00758","DOIUrl":"https://doi.org/10.1556/606.2023.00758","url":null,"abstract":"The multi-aquifer system of the Nubian aquifer in central Sudan hydrogeological system was simulated using a three-dimensional steady-state model. The goal of the study is to detect the effect of pumping on the groundwater flow and thus, the aquifer productivity. The conceptual model of the study area was built based on the available geological and hydrogeological data guided by geophysical survey. Processing MODFLOW numerical code was used to calculate the hydraulic head and water balance under the existing boundary conditions. The model accurately simulated the hydraulic head with a determination coefficient of 0.88. The calibrated model indicated that the change in storage is 0.56 m3/day indicating the study area constitutes highly productive zone and is recommended for groundwater developments.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48252896","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}
Real-time deformation measurements have the potential to be used in a wide range of civil and structural engineering applications. This paper introduces an algorithm that utilizes time-based photogrammetry to measure deformations in real-time. The hardware used in the algorithm consists of a camera and a computer that runs camera-control software and a MATLAB code. The code is responsible for detecting the approximate locations of the circular targets using normalized 2D cross-correlation and performing the sub-pixel measurement of the center by fitting an ellipse on the edges of the circular target. During an experimental load test of a concrete slab outfitted with Ringed Automated Detection targets, a series of images were taken at different loads. The coordinates of the targets were measured using the edge-ellipse operator, least-squares matching, and digital image correlation methods. The edge-ellipse operator has proven to be an effective method of measuring the image coordinates of circular targets.
{"title":"Comparison of image operators for time-based photogrammetry","authors":"Andrej Hideghéty, M. Fraštia","doi":"10.1556/606.2023.00771","DOIUrl":"https://doi.org/10.1556/606.2023.00771","url":null,"abstract":"Real-time deformation measurements have the potential to be used in a wide range of civil and structural engineering applications. This paper introduces an algorithm that utilizes time-based photogrammetry to measure deformations in real-time. The hardware used in the algorithm consists of a camera and a computer that runs camera-control software and a MATLAB code. The code is responsible for detecting the approximate locations of the circular targets using normalized 2D cross-correlation and performing the sub-pixel measurement of the center by fitting an ellipse on the edges of the circular target. During an experimental load test of a concrete slab outfitted with Ringed Automated Detection targets, a series of images were taken at different loads. The coordinates of the targets were measured using the edge-ellipse operator, least-squares matching, and digital image correlation methods. The edge-ellipse operator has proven to be an effective method of measuring the image coordinates of circular targets.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42886760","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 project is the design of the tourism service station in the coastal park, which not only meets the basic functional requirements of the park service station but also reconfigures the station space with the regional cultural characteristics of Qingdao. The design process is mainly conceived in five aspects: locality, landscape, identity, symbolization, and diversification. It integrates the cultural characteristics of Qingdao coastal tourism with the park landscape to create a tourist rest space with diversified experiences. The purpose of this paper is to explore the interface between the stations' design and the various links of the cultural tourism industry chain. The project will be created as the “Window of Qingdao” in Baisha River Park.
{"title":"Park station design in the context of cultural tourism integration","authors":"D. He, Shasha Liu","doi":"10.1556/606.2023.00811","DOIUrl":"https://doi.org/10.1556/606.2023.00811","url":null,"abstract":"This project is the design of the tourism service station in the coastal park, which not only meets the basic functional requirements of the park service station but also reconfigures the station space with the regional cultural characteristics of Qingdao. The design process is mainly conceived in five aspects: locality, landscape, identity, symbolization, and diversification. It integrates the cultural characteristics of Qingdao coastal tourism with the park landscape to create a tourist rest space with diversified experiences. The purpose of this paper is to explore the interface between the stations' design and the various links of the cultural tourism industry chain. The project will be created as the “Window of Qingdao” in Baisha River Park.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46247201","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}
Muthusamy Saradha, T. Ilango, Shanmugam Annamalai, Krishnamurthy Muthumani
An experimental study was carried out on geo-polymer and reinforced concrete beams to evaluate the flexural behavior of the beams for the structural grade of M30 concrete. The results show that the geo-polymer concrete beams exhibit similar flexural strength when compared to reinforced concrete beams. The split tensile strength, stiffness characters, the energy capacity and ductility relationship were also found with satisfactory results. The deflection and the stiffness degradation at the salient stages were found to be similar and thus the geo-polymer concrete beams find a good alternative to reinforced concrete beams under flexural behavior.
{"title":"Flexural behavior of reinforced geo-polymer concrete beams at ambient temperature","authors":"Muthusamy Saradha, T. Ilango, Shanmugam Annamalai, Krishnamurthy Muthumani","doi":"10.1556/606.2023.00829","DOIUrl":"https://doi.org/10.1556/606.2023.00829","url":null,"abstract":"An experimental study was carried out on geo-polymer and reinforced concrete beams to evaluate the flexural behavior of the beams for the structural grade of M30 concrete. The results show that the geo-polymer concrete beams exhibit similar flexural strength when compared to reinforced concrete beams. The split tensile strength, stiffness characters, the energy capacity and ductility relationship were also found with satisfactory results. The deflection and the stiffness degradation at the salient stages were found to be similar and thus the geo-polymer concrete beams find a good alternative to reinforced concrete beams under flexural behavior.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45596622","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}
Recent studies showed a significant peak of the salt contamination in the Tisza River that exceeded ten times over the average level. The document summarizes the works performed on the investigation of ground displacement using multi-temporal satellite radar interferometry technique in Solotvyno mine located in Tiachiv region. Multi-temporal InSAR aims to identify coherent radar targets exhibiting high phase stability over the entire observation period and derives point data with locations corresponding mainly to the point-wise, man-made features. The middle area with no persecuted targets may correspond to the substantial physical changes of the surface caused by activities like mining or tunneling, adding, or removing structures or their components, and motion perceptible in one pixel.
{"title":"Multi-temporal insar analysis of ground displacement in solotvyno","authors":"M. Hlinkova, M. Zeleňáková, V. Mikita","doi":"10.1556/606.2023.00785","DOIUrl":"https://doi.org/10.1556/606.2023.00785","url":null,"abstract":"Recent studies showed a significant peak of the salt contamination in the Tisza River that exceeded ten times over the average level. The document summarizes the works performed on the investigation of ground displacement using multi-temporal satellite radar interferometry technique in Solotvyno mine located in Tiachiv region. Multi-temporal InSAR aims to identify coherent radar targets exhibiting high phase stability over the entire observation period and derives point data with locations corresponding mainly to the point-wise, man-made features. The middle area with no persecuted targets may correspond to the substantial physical changes of the surface caused by activities like mining or tunneling, adding, or removing structures or their components, and motion perceptible in one pixel.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46918936","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}
Levente Tugyi, Z. Siménfalvi, G. Szepesi, C. Kecskés, Zoltán Kerekes, Tamás Sári
In the event of a flammable liquid, gas, or vapor release the first step is to identify the type of outflow, which can fall into two categories sonic or subsonic. The two types of outflows carry different flow characteristics, which effect on the extent of the potentially explosive areas. In case of subsonic outflow, a short jet is formed without turbulent flow conditions at low velocity, which appears more concentrated around the source of release. With sonic outflow, a high velocity jet is formed with turbulent flow properties, which can extend further away from the source of release. The simulations examine the lower explosion limit of the flammable medium around the vessel where LEL20% or LEL40%. In addition, high temperature methane gas release was also presented.
{"title":"CFD modeling of subsonic and sonic methane gas release and dispersion","authors":"Levente Tugyi, Z. Siménfalvi, G. Szepesi, C. Kecskés, Zoltán Kerekes, Tamás Sári","doi":"10.1556/606.2023.00789","DOIUrl":"https://doi.org/10.1556/606.2023.00789","url":null,"abstract":"In the event of a flammable liquid, gas, or vapor release the first step is to identify the type of outflow, which can fall into two categories sonic or subsonic. The two types of outflows carry different flow characteristics, which effect on the extent of the potentially explosive areas. In case of subsonic outflow, a short jet is formed without turbulent flow conditions at low velocity, which appears more concentrated around the source of release. With sonic outflow, a high velocity jet is formed with turbulent flow properties, which can extend further away from the source of release. The simulations examine the lower explosion limit of the flammable medium around the vessel where LEL20% or LEL40%. In addition, high temperature methane gas release was also presented.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43710167","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}
There is currently no accurate calculation procedure for determining the lateral-torsional buckling resistance of trapezoidally corrugated web girders. Therefore, a detailed investigation is performed in the frame of an experimental and numerical research program at the Department of Structural Engineering of the Budapest University of Technology and Economics. Based on the previous experimental results, a numerical model is developed to be used to determine the lateral-torsional buckling resistance by using deterministic method. The effect of flange size, corrugation geometry and boundary conditions are investigated. An improved design method is developed for the determination of the lateral-torsional buckling resistance of trapezoidally corrugated web girders.
{"title":"Lateral-torsional buckling resistance of corrugated web girders","authors":"E. Bärnkopf, B. Jáger, B. Kövesdi","doi":"10.1556/606.2023.00797","DOIUrl":"https://doi.org/10.1556/606.2023.00797","url":null,"abstract":"There is currently no accurate calculation procedure for determining the lateral-torsional buckling resistance of trapezoidally corrugated web girders. Therefore, a detailed investigation is performed in the frame of an experimental and numerical research program at the Department of Structural Engineering of the Budapest University of Technology and Economics. Based on the previous experimental results, a numerical model is developed to be used to determine the lateral-torsional buckling resistance by using deterministic method. The effect of flange size, corrugation geometry and boundary conditions are investigated. An improved design method is developed for the determination of the lateral-torsional buckling resistance of trapezoidally corrugated web girders.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47763540","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：