Nature-like fishway arrangements are commonly used because these structures imitate the characteristics of natural rivers and effectively allow fish to migrate past river sections blocked by hydraulic structures. In this paper, physical models were analyzed, and the velocity distributions of two different fishway structures (Types I and II) were compared. Results showed that the maximum mainstream velocity of the Type I structure was 5.3% lower than that of the Type II structure. However, the average mainstream velocity of the Type I structure was 21.1% greater than that of the Type II structure. The total per-cycle length of the mainstream path in the Type II structure was 2.1 times greater than that of the Type I structure, which indicated that the length of the mainstream path was somewhat proportional to the average velocity of the mainstream. When the flow rate was kept constant, increases in the velocity of the main flow associated with changes in the internal structure of the fishway decreased the average velocity of the main flow, while decreases in the total length of the flow path led to increases in the average velocity of the main flow. Due to frictional head loss along the fishway and local head loss, as well as the overlaps between these factors, the overall flow rate gradually decreased every cycle, despite periodic fluctuations.
{"title":"THE HYDRAULICS OF NATURE-LIKE FISHWAYS","authors":"X. Mao, Shengyu Huang, Yuchen Xu, Zhong Cheng, Jiehao Zhang","doi":"10.14311/cej.2021.04.0063","DOIUrl":"https://doi.org/10.14311/cej.2021.04.0063","url":null,"abstract":"Nature-like fishway arrangements are commonly used because these structures imitate the characteristics of natural rivers and effectively allow fish to migrate past river sections blocked by hydraulic structures. In this paper, physical models were analyzed, and the velocity distributions of two different fishway structures (Types I and II) were compared. Results showed that the maximum mainstream velocity of the Type I structure was 5.3% lower than that of the Type II structure. However, the average mainstream velocity of the Type I structure was 21.1% greater than that of the Type II structure. The total per-cycle length of the mainstream path in the Type II structure was 2.1 times greater than that of the Type I structure, which indicated that the length of the mainstream path was somewhat proportional to the average velocity of the mainstream. When the flow rate was kept constant, increases in the velocity of the main flow associated with changes in the internal structure of the fishway decreased the average velocity of the main flow, while decreases in the total length of the flow path led to increases in the average velocity of the main flow. Due to frictional head loss along the fishway and local head loss, as well as the overlaps between these factors, the overall flow rate gradually decreased every cycle, despite periodic fluctuations.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80981093","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}
Pub Date : 2021-12-31DOI: 10.14311/cej.2021.04.0068
Aleš Polák
Traditional precast reinforced concrete structures are characterised by joints of individual components executed with the use of cement grouts or mortars, or by welding reinforcement. The joints produced in this way cannot be demounted in the case of need without damaging the precast components. Demountable precast structures with a long life cycle enable repeated assembly and demounting thus contributing to the saving of the basic input resources and the environment. The main feature of demountable precast structures are patent-protected joints which allow the assembly of the precast components without the necessity of using “wet” processes. The article addresses the characteristics of a demountable girder - column joint. It presents the results of static load tests carried out within extensive experimental research. To conclude, the article specifies the benefits and the applications of demountable structures.
{"title":"Demountable Column - Girder Joint","authors":"Aleš Polák","doi":"10.14311/cej.2021.04.0068","DOIUrl":"https://doi.org/10.14311/cej.2021.04.0068","url":null,"abstract":"Traditional precast reinforced concrete structures are characterised by joints of individual components executed with the use of cement grouts or mortars, or by welding reinforcement. The joints produced in this way cannot be demounted in the case of need without damaging the precast components. Demountable precast structures with a long life cycle enable repeated assembly and demounting thus contributing to the saving of the basic input resources and the environment. The main feature of demountable precast structures are patent-protected joints which allow the assembly of the precast components without the necessity of using “wet” processes. The article addresses the characteristics of a demountable girder - column joint. It presents the results of static load tests carried out within extensive experimental research. To conclude, the article specifies the benefits and the applications of demountable structures.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72816819","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}
Pub Date : 2021-12-31DOI: 10.14311/cej.2021.04.0064
S. Šarvaicová, V. Borzovič
The paper deals with the loading test results of an experimental reinforced concrete flat slab fragment, which was supported by an elongated rectangular column. The slab specimens were 200 mm thick and were designed without any shear reinforcement. By experimentally obtained punching shear resistance, the accuracy of the standard design models for prediction punching resistance was compared. The results of the experiments were also compared with the results of a numerical non-linear analysis performed in the Atena program.
{"title":"Experimental verification of punching shear resistance of flat slab fragments","authors":"S. Šarvaicová, V. Borzovič","doi":"10.14311/cej.2021.04.0064","DOIUrl":"https://doi.org/10.14311/cej.2021.04.0064","url":null,"abstract":"The paper deals with the loading test results of an experimental reinforced concrete flat slab fragment, which was supported by an elongated rectangular column. The slab specimens were 200 mm thick and were designed without any shear reinforcement. By experimentally obtained punching shear resistance, the accuracy of the standard design models for prediction punching resistance was compared. The results of the experiments were also compared with the results of a numerical non-linear analysis performed in the Atena program.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73328060","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0051
Szilárd Kanizsár
In 3D geotechnical modelling it is essential for the realistic simulation of soil behavior that the parameters of the hardening soil with small strain constitutive model are specified appropriately. The possibility of deriving these parameters for very stiff cohesive soils similar to the so called Kiscell clay that has a significant role in deep construction projects in Budapest, from laboratory and field tests is rather limited. The results of the pile load test completed for the MOL Campus high-rise building project proved to be useful data source. The article presents the circumstances of the quoted Osterberg-cell pile load tests and the modelling of the pile performed by the above-mentioned soil model. The parameters specified on the basis of laboratory tests - and in absence of those based on literature - data can be fine-tuned by approaching the load test results.
{"title":"BACK ANALYSIS OF OSTERBERG-CELL PILE LOAD TEST BY MEANS OF THREE-DIMENSIONAL GEOTECHNICAL MODELING","authors":"Szilárd Kanizsár","doi":"10.14311/cej.2021.03.0051","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0051","url":null,"abstract":"In 3D geotechnical modelling it is essential for the realistic simulation of soil behavior that the parameters of the hardening soil with small strain constitutive model are specified appropriately. The possibility of deriving these parameters for very stiff cohesive soils similar to the so called Kiscell clay that has a significant role in deep construction projects in Budapest, from laboratory and field tests is rather limited. The results of the pile load test completed for the MOL Campus high-rise building project proved to be useful data source. The article presents the circumstances of the quoted Osterberg-cell pile load tests and the modelling of the pile performed by the above-mentioned soil model. The parameters specified on the basis of laboratory tests - and in absence of those based on literature - data can be fine-tuned by approaching the load test results.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75703587","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0052
Q. Zhang
The large-span roof structure is favored by architects and structural engineers all over the world for its novel architectural shape and reasonable structural characteristics. It has been widely used in large public buildings such as sports buildings, memorial buildings and cultural buildings. Based on the structure design of the fourth national college students’ competition winning entries for the model, this paper introduces the stadium upper cantilever roof structure model selection, process design, interface, etc. Using the finite element software ANSYS to analyze the model structure under different load conditions of the static performance, we acquire its natural frequency. The results show that the model meets both the strength and stiffness requirement.
{"title":"RESEARCH ON FORCE AND MODAL ANALYSIS OF THE CANTILEVER ROOF MODEL OF A STADIUM","authors":"Q. Zhang","doi":"10.14311/cej.2021.03.0052","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0052","url":null,"abstract":"The large-span roof structure is favored by architects and structural engineers all over the world for its novel architectural shape and reasonable structural characteristics. It has been widely used in large public buildings such as sports buildings, memorial buildings and cultural buildings. Based on the structure design of the fourth national college students’ competition winning entries for the model, this paper introduces the stadium upper cantilever roof structure model selection, process design, interface, etc. Using the finite element software ANSYS to analyze the model structure under different load conditions of the static performance, we acquire its natural frequency. The results show that the model meets both the strength and stiffness requirement.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79537516","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0045
Helena Hexnerová
The main objective of this paper is to compare student projects of café and restaurant interior in the preserved building of the rectory in a monument reservation in the centre of the town Úštěk. There are six projects dealing with suitability of café and restaurant in the building of the rectory. Students designed interiors and they also worked on the layout of the building with the adjacent courtyard and farm buildings, including their modifications. The article analyses and compares individual student works in terms of the use of areas for individual functions of operation and the number of seats for guests.
{"title":"ANALYSIS OF A LAYOUT SOLUTION OF DESIGN BY CTU STUDENTS – ÚŠTĚK RECTORY","authors":"Helena Hexnerová","doi":"10.14311/cej.2021.03.0045","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0045","url":null,"abstract":"The main objective of this paper is to compare student projects of café and restaurant interior in the preserved building of the rectory in a monument reservation in the centre of the town Úštěk. There are six projects dealing with suitability of café and restaurant in the building of the rectory. Students designed interiors and they also worked on the layout of the building with the adjacent courtyard and farm buildings, including their modifications. The article analyses and compares individual student works in terms of the use of areas for individual functions of operation and the number of seats for guests.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88684617","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0053
J. Rilatupa
The Sion Church is one of the cultural heritage buildings that still need to be maintained, given its condition that has begun to deteriorate. It is fitting that a cultural heritage building needs to be preserved, especially as a heritage asset in the capital that is more than three centuries old in dire need of conservation action. Meanwhile, routine monitoring and evaluation activities are one of the tools in preserving cultural heritage buildings. The purpose of this activity is to find out and collect data on the maintenance of a cultural heritage building so that any damage found in the cultural heritage building can be followed up. It is intended that cultural heritage buildings can be maintained and their existence is preserved because there are things that are valuable to human civilization including religion, science, culture, etc. The conditions of ability and upkeep of the Sion Church Building were assessed on the basis of weighting assessments namely in design and upkeep work suitable which was adjusted for Indonesia (humid tropical climate). Based on the results of the examination, obtained that the ability quality of the Sion Church building was 43.70 that was included in the moderate damaged maintenance condition category
{"title":"DAMAGE ASSESSMENT OF CONSTRUCTION COMPONENTS","authors":"J. Rilatupa","doi":"10.14311/cej.2021.03.0053","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0053","url":null,"abstract":"The Sion Church is one of the cultural heritage buildings that still need to be maintained, given its condition that has begun to deteriorate. It is fitting that a cultural heritage building needs to be preserved, especially as a heritage asset in the capital that is more than three centuries old in dire need of conservation action. Meanwhile, routine monitoring and evaluation activities are one of the tools in preserving cultural heritage buildings. The purpose of this activity is to find out and collect data on the maintenance of a cultural heritage building so that any damage found in the cultural heritage building can be followed up. It is intended that cultural heritage buildings can be maintained and their existence is preserved because there are things that are valuable to human civilization including religion, science, culture, etc. The conditions of ability and upkeep of the Sion Church Building were assessed on the basis of weighting assessments namely in design and upkeep work suitable which was adjusted for Indonesia (humid tropical climate). Based on the results of the examination, obtained that the ability quality of the Sion Church building was 43.70 that was included in the moderate damaged maintenance condition category","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74636300","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0057
D. Zahradník
Using drones with different purposes than only taking photos is nowadays the main direction of drone development. Drones are made for package delivery, people transport, etc. Drone equipped by GNSS RTK and prism can be used as orientation point for the free station. The idea is using drone to get coordinates of total stations inappropriate for GNSS. such as high buildings and forest. The drone can fly above the obstacle causing inappropriate, so the GNSS will compute the position coordinates correctly. Total station will measure distance and angles on prism to get free station coordinates. This article deals with the accuracy of using two points in the free station task. Accuracy of measurement and data is based on real values. Drone can be used as the target if it is not windy, the position accuracy of the target on drone is 5 cm. Wind has no effect on the vertical position accuracy of the the drone. The results show that the same principles and limitations must be observed when measuring the free station task. Horizontal angle between orientation points must be bigger than 100 gon and the zenith angle must be at least 50 gon. The distance between orientation and free station must longer than consequent measured points.
{"title":"FREE STATION TASK WITH DRONE","authors":"D. Zahradník","doi":"10.14311/cej.2021.03.0057","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0057","url":null,"abstract":"Using drones with different purposes than only taking photos is nowadays the main direction of drone development. Drones are made for package delivery, people transport, etc. Drone equipped by GNSS RTK and prism can be used as orientation point for the free station. The idea is using drone to get coordinates of total stations inappropriate for GNSS. such as high buildings and forest. The drone can fly above the obstacle causing inappropriate, so the GNSS will compute the position coordinates correctly. Total station will measure distance and angles on prism to get free station coordinates. This article deals with the accuracy of using two points in the free station task. Accuracy of measurement and data is based on real values. Drone can be used as the target if it is not windy, the position accuracy of the target on drone is 5 cm. Wind has no effect on the vertical position accuracy of the the drone. The results show that the same principles and limitations must be observed when measuring the free station task. Horizontal angle between orientation points must be bigger than 100 gon and the zenith angle must be at least 50 gon. The distance between orientation and free station must longer than consequent measured points.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91266091","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0056
Chenyang Yuan, X. Xu, Xiangtian Nie, W. Bai
Extreme conditions will cause the water level of high fill canal segment to change suddenly, which will affect the velocity and pore pressure of the slope. In this paper, numerical method is used to study the influence of water level sudden change on seepage characteristics of high fill canal segment. HyperMesh software is used to establish the finite element model of typical high fill canal segment under complex foundation conditions. Through the combination of secondary development program and fluid-structure coupling calculation method, the fluid structure cou-pling effect of canal under sudden change of water level is analyzed in ABAQUS. The results show that when the water level changes suddenly, the pore pressure below the free water surface and the velocity near the free surface will be greatly affected.
{"title":"Study on the Influence of Sudden Change of Water Level on High Fill Canal Segment","authors":"Chenyang Yuan, X. Xu, Xiangtian Nie, W. Bai","doi":"10.14311/cej.2021.03.0056","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0056","url":null,"abstract":"Extreme conditions will cause the water level of high fill canal segment to change suddenly, which will affect the velocity and pore pressure of the slope. In this paper, numerical method is used to study the influence of water level sudden change on seepage characteristics of high fill canal segment. HyperMesh software is used to establish the finite element model of typical high fill canal segment under complex foundation conditions. Through the combination of secondary development program and fluid-structure coupling calculation method, the fluid structure cou-pling effect of canal under sudden change of water level is analyzed in ABAQUS. The results show that when the water level changes suddenly, the pore pressure below the free water surface and the velocity near the free surface will be greatly affected.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81882958","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}
Pub Date : 2021-10-25DOI: 10.14311/cej.2021.03.0054
Long Liu, Y. Bi
To explore the stress of the tower-beam-pier joint zone of a cable-stayed bridge under different systems, the submodel method in the finite element software ABAQUS was used to establish the local model of the tower-beam-pier joint zone of the bridge. At the same time, Midas/Civil was used to establish the rod system finite element model of the whole bridge. The correctness of the local model was verified by comparing the results of the finite element model and the local model. Then, by changing the combination mode of tower beam pier, the stress comparison analysis of the joint zone of the tower-beam-pier under different systems was carried out. The results showed the stress distribution of the semi-floating system was more reasonable than that of the rigid frame system and the consolidation system. In the use of the three different systems, there was concentrated tensile stress at the chamfer of the web and the bottom plate, where the steel bars should be added. In the rigid frame system, the deflection of the main beam under the load was the smallest, and the maximum displacement occurred at the boundary section, with the value of only 2.668mm.
{"title":"COMPARATIVE ANALYSIS OF SPATIAL STRESS IN THE JOINT ZONE OF TOWER PIER UNDER DIFFERENT SYSTEMS OF CABLE-STAYED BRIDGE","authors":"Long Liu, Y. Bi","doi":"10.14311/cej.2021.03.0054","DOIUrl":"https://doi.org/10.14311/cej.2021.03.0054","url":null,"abstract":"To explore the stress of the tower-beam-pier joint zone of a cable-stayed bridge under different systems, the submodel method in the finite element software ABAQUS was used to establish the local model of the tower-beam-pier joint zone of the bridge. At the same time, Midas/Civil was used to establish the rod system finite element model of the whole bridge. The correctness of the local model was verified by comparing the results of the finite element model and the local model. Then, by changing the combination mode of tower beam pier, the stress comparison analysis of the joint zone of the tower-beam-pier under different systems was carried out. The results showed the stress distribution of the semi-floating system was more reasonable than that of the rigid frame system and the consolidation system. In the use of the three different systems, there was concentrated tensile stress at the chamfer of the web and the bottom plate, where the steel bars should be added. In the rigid frame system, the deflection of the main beam under the load was the smallest, and the maximum displacement occurred at the boundary section, with the value of only 2.668mm.","PeriodicalId":21974,"journal":{"name":"Stavební obzor - Civil Engineering Journal","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85068901","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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