Pub Date : 2024-03-29DOI: 10.24425/ace.2024.148911
Michał Kubrak
The aim of this research was to experimentally analyse the possibility of using a rubber hose placed inside a pipeline to mitigate the water hammer phenomenon. The experiments were conducted using a steel pipeline with an inner diameter of 53 mm and an EPDM rubber hose with a diameter of 6 mm. Hydraulic transients were induced by a rapid closure of the valve located at the downstream end of the pipeline system. In order to analyse the influence of steady-state flow conditions on the maximum pressure increase, measurements were carried out for different values of initial pressure and discharge. The experimental results indicate that placing a rubber hose inside a pipeline can substantially attenuate valve-induced pressure oscillations. It was observed that the initial pressure has a significant influence on the capacity of the rubber hose to dampen the water hammer phenomenon. Comparative numerical calculations were performed using the Brunone–Vitkovský instant acceleration-based model of unsteady friction. It was demonstrated that this approach does not allow satisfactory reproduction of the observed pressure oscillations due to the viscoelastic properties of the EPDM hose used in the tests.
{"title":"Water hammer mitigation by internal rubber hose","authors":"Michał Kubrak","doi":"10.24425/ace.2024.148911","DOIUrl":"https://doi.org/10.24425/ace.2024.148911","url":null,"abstract":"The aim of this research was to experimentally analyse the possibility of using a rubber hose placed inside a pipeline to mitigate the water hammer phenomenon. The experiments were conducted using a steel pipeline with an inner diameter of 53 mm and an EPDM rubber hose with a diameter of 6 mm. Hydraulic transients were induced by a rapid closure of the valve located at the downstream end of the pipeline system. In order to analyse the influence of steady-state flow conditions on the maximum pressure increase, measurements were carried out for different values of initial pressure and discharge. The experimental results indicate that placing a rubber hose inside a pipeline can substantially attenuate valve-induced pressure oscillations. It was observed that the initial pressure has a significant influence on the capacity of the rubber hose to dampen the water hammer phenomenon. Comparative numerical calculations were performed using the Brunone–Vitkovský instant acceleration-based model of unsteady friction. It was demonstrated that this approach does not allow satisfactory reproduction of the observed pressure oscillations due to the viscoelastic properties of the EPDM hose used in the tests.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368700","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 : 2024-03-29DOI: 10.24425/ace.2024.148930
Feng Chen, Yun Sun, Shuxuan Sun, Da Song, Yangbing Liu
The treelike structure links members and transfers loads via its solitary cast steel joint with branches. Therefore, the joint’s bearing capacity significantly affects the treelike structure’s stability, security, and economics. This paper utilized experimental verification and numerical modeling to examine the mechanical behavior of cast-steel joints with branches in the treelike structure under various loading conditions. Then, researchers investigated the failure process and mechanism of joints, and the three most common failure modes were outlined. Furthermore, the researchers proposed the bearing capacity calculation formula based on the common failure modes. The results show that the three common failure modes of the cast-steel joints with branches under different loading conditions are the failure in the joint core area under the axial load, the failure in the main pipe compression side under eccentric load, and the failure in the compression side of the single branch pipe root when the single branch pipe is under the uneven load. The suggested empirical calculation method can serve as a reference point for similar engineering practices design.
{"title":"Study on failure modes and calculation method of the cast steel joint with branches in treelike structure","authors":"Feng Chen, Yun Sun, Shuxuan Sun, Da Song, Yangbing Liu","doi":"10.24425/ace.2024.148930","DOIUrl":"https://doi.org/10.24425/ace.2024.148930","url":null,"abstract":"The treelike structure links members and transfers loads via its solitary cast steel joint with branches. Therefore, the joint’s bearing capacity significantly affects the treelike structure’s stability, security, and economics. This paper utilized experimental verification and numerical modeling to examine the mechanical behavior of cast-steel joints with branches in the treelike structure under various loading conditions. Then, researchers investigated the failure process and mechanism of joints, and the three most common failure modes were outlined. Furthermore, the researchers proposed the bearing capacity calculation formula based on the common failure modes. The results show that the three common failure modes of the cast-steel joints with branches under different loading conditions are the failure in the joint core area under the axial load, the failure in the main pipe compression side under eccentric load, and the failure in the compression side of the single branch pipe root when the single branch pipe is under the uneven load. The suggested empirical calculation method can serve as a reference point for similar engineering practices design.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140365019","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 : 2024-03-29DOI: 10.24425/ace.2024.148931
Yan Wu
The excavation of adjacent pits following the initial foundation pit excavation can significantly influence ground settlement. Using a foundation pit excavation project in Changzhou as a prototype, this study employed the numerical simulation method in conjunction with the HSS model to analyze the settlement deformation characteristics of the original excavation and compare them with the recorded monitoring values. In this study, the analysis focused on the ground settlement between two pits by varying the spacing between them at different excavation depths. The findings revealed that the ground settlement does not exhibit a significant increase when the new pit is excavated at a shallow depth. However, it rapidly increases when the excavation depth of the new pit surpasses that of the existing pit. Furthermore, an increase in the distance between the two pits causes the maximum settlement position to shift towards the edge of the new pit. The maximum ground settlement is found to have a linear relationship with both the maximum horizontal displacement of the two pits and the spacing between them.
{"title":"Ground settlement and estimation of maximum settlement value in adjacent foundation pit excavation","authors":"Yan Wu","doi":"10.24425/ace.2024.148931","DOIUrl":"https://doi.org/10.24425/ace.2024.148931","url":null,"abstract":"The excavation of adjacent pits following the initial foundation pit excavation can significantly influence ground settlement. Using a foundation pit excavation project in Changzhou as a prototype, this study employed the numerical simulation method in conjunction with the HSS model to analyze the settlement deformation characteristics of the original excavation and compare them with the recorded monitoring values. In this study, the analysis focused on the ground settlement between two pits by varying the spacing between them at different excavation depths. The findings revealed that the ground settlement does not exhibit a significant increase when the new pit is excavated at a shallow depth. However, it rapidly increases when the excavation depth of the new pit surpasses that of the existing pit. Furthermore, an increase in the distance between the two pits causes the maximum settlement position to shift towards the edge of the new pit. The maximum ground settlement is found to have a linear relationship with both the maximum horizontal displacement of the two pits and the spacing between them.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366608","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 : 2024-03-29DOI: 10.24425/ace.2024.148928
Maciej Maślakowski, Anna Lejzerowicz, Grzegorz Pacanowski, Rafał Kuszyk
Appropriate design in linear construction depends on many factors, including detailed geological conditions. One of the biggest problems are unrecognized erosion forms, in particular karst ones, which have a huge impact on the design and subsequent operation of roads. For this purpose, in addition to conventional methods such as drilling or geotechnical probing, which are point-based, non-invasive spatial geophysical methods are used. This article presents an example of the use of geoelectrical surveys, Electrical Resistivity Tomography (ERT) for the recognition of karst zones for linear investments. The article describes ERT investigations, which to some extent allows to identify dangerous karst phenomena occurring in the Lublin Upland (Poland), which are of great importance at the design stage of roads and in their further safe operation. Non-invasive geophysical research has been verified and confirmed by traditional geotechnical research, which confirms the effectiveness of their use. The Electrical Resistivity Tomography was used as a method providing a broader spectrum of knowledge on the spatial arrangement of soil layers in the subgrade of the planned road investments. It also enabled a more accurate, more detailed interpretation of geotechnical studies. The described geophysical investigations opens wide possibilities for their application to researchers. In the future, non-invasive methods have a chance to become as reliable as geotechnical methods, but this requires a lot of research to improve the effectiveness and accuracy of the interpretation of the obtained results.
{"title":"The use of non-invasive ERT method to diagnose karst in roadengineering in the Lublin Upland (Poland)","authors":"Maciej Maślakowski, Anna Lejzerowicz, Grzegorz Pacanowski, Rafał Kuszyk","doi":"10.24425/ace.2024.148928","DOIUrl":"https://doi.org/10.24425/ace.2024.148928","url":null,"abstract":"Appropriate design in linear construction depends on many factors, including detailed geological conditions. One of the biggest problems are unrecognized erosion forms, in particular karst ones, which have a huge impact on the design and subsequent operation of roads. For this purpose, in addition to conventional methods such as drilling or geotechnical probing, which are point-based, non-invasive spatial geophysical methods are used. This article presents an example of the use of geoelectrical surveys, Electrical Resistivity Tomography (ERT) for the recognition of karst zones for linear investments. The article describes ERT investigations, which to some extent allows to identify dangerous karst phenomena occurring in the Lublin Upland (Poland), which are of great importance at the design stage of roads and in their further safe operation. Non-invasive geophysical research has been verified and confirmed by traditional geotechnical research, which confirms the effectiveness of their use. The Electrical Resistivity Tomography was used as a method providing a broader spectrum of knowledge on the spatial arrangement of soil layers in the subgrade of the planned road investments. It also enabled a more accurate, more detailed interpretation of geotechnical studies. The described geophysical investigations opens wide possibilities for their application to researchers. In the future, non-invasive methods have a chance to become as reliable as geotechnical methods, but this requires a lot of research to improve the effectiveness and accuracy of the interpretation of the obtained results.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366776","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 : 2024-03-29DOI: 10.24425/ace.2024.148917
Fengfeng Guo, Yupeng Chen, Yongjie Zhang, Qi Feng, Da Cui
The ground disturbance caused by the tunnel construction will inevitably have an impact on the upper part of the constructed tunnel structure, and the railroad tunnel requires a very high level of control over the structural settlement deformation. For the problem of double-hole tunnel under the built tunnel, this paper takes Chongqing Mingyue Mountain Tunnel under the built Shanghai-Rong Railway Paihua Cave tunnel and Zheng-Yu Railway tunnel as the engineering background, and starts from the mechanism of ground loss caused by tunnel excavation, firstly, the settlement at the height of the existing tunnel strata is obtained through theoretical analysis, and the new Mingyue Mountain Tunnel under the Shanghai-Rong Railway tunnel is determined to be a more dangerous section. Further simulate and calculate the dynamic excavation process of the new double-hole tunnel underpass, and study the settlement deformation law of the Mingyue Mountain Tunnel underpassing the Hurong Railway Tunnel. According to the requirements of railroad tunnel for settlement deformation control, the new tunnel is determined to be constructed by step method to ensure the safety of railroad tunnel. The shortcomings of the theoretical calculation are analyzed to illustrate the important role of numerical simulation in the evaluation of tunnel underpass projects.
{"title":"Safety assessment of the construction of double track tunnels underneah exsiting railway tunnels","authors":"Fengfeng Guo, Yupeng Chen, Yongjie Zhang, Qi Feng, Da Cui","doi":"10.24425/ace.2024.148917","DOIUrl":"https://doi.org/10.24425/ace.2024.148917","url":null,"abstract":"The ground disturbance caused by the tunnel construction will inevitably have an impact on the upper part of the constructed tunnel structure, and the railroad tunnel requires a very high level of control over the structural settlement deformation. For the problem of double-hole tunnel under the built tunnel, this paper takes Chongqing Mingyue Mountain Tunnel under the built Shanghai-Rong Railway Paihua Cave tunnel and Zheng-Yu Railway tunnel as the engineering background, and starts from the mechanism of ground loss caused by tunnel excavation, firstly, the settlement at the height of the existing tunnel strata is obtained through theoretical analysis, and the new Mingyue Mountain Tunnel under the Shanghai-Rong Railway tunnel is determined to be a more dangerous section. Further simulate and calculate the dynamic excavation process of the new double-hole tunnel underpass, and study the settlement deformation law of the Mingyue Mountain Tunnel underpassing the Hurong Railway Tunnel. According to the requirements of railroad tunnel for settlement deformation control, the new tunnel is determined to be constructed by step method to ensure the safety of railroad tunnel. The shortcomings of the theoretical calculation are analyzed to illustrate the important role of numerical simulation in the evaluation of tunnel underpass projects.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140367387","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 : 2024-03-29DOI: 10.24425/ace.2024.148924
Jiawei Wang, Feifei Ying
Due to the increase in traffic volume, load level, and service life of existing bridges, the bending bearing capacity of reinforced concrete beams (hereinafter referred to as RC beams) has decreased, leading to safety issues. In order to solve the problem of insufficient flexural bearing capacity of RC beams, this article adopts the method of ultra-high performance concrete (UHPC) flexural strengthening RC beams, establishes a finite element model of UHPC-RC reinforcement system, and conducts stress analysis with reinforcement thickness, reinforcement range, reinforcement form, and reinforcement height as parameters to determine the optimal scheme of the reinforcement system. Based on the calculation results, a theoretical formula for the maximum principal stress and maximum deflection of the reinforcement system is proposed. To verify the feasibility of the plan, a reinforcement design was carried out on an existing beam, and it was found that the bending bearing capacity of the RC beam increased by 21%; the high tensile strength of UHPC and the addition of steel fibers have a good limiting effect on cracks; The steel plate of the reinforcement system can be used as a template, reducing construction costs and having good economy.
{"title":"Research on the design method of flexural capacity of RC beams strengthen by ultra-high-performance concrete","authors":"Jiawei Wang, Feifei Ying","doi":"10.24425/ace.2024.148924","DOIUrl":"https://doi.org/10.24425/ace.2024.148924","url":null,"abstract":"Due to the increase in traffic volume, load level, and service life of existing bridges, the bending bearing capacity of reinforced concrete beams (hereinafter referred to as RC beams) has decreased, leading to safety issues. In order to solve the problem of insufficient flexural bearing capacity of RC beams, this article adopts the method of ultra-high performance concrete (UHPC) flexural strengthening RC beams, establishes a finite element model of UHPC-RC reinforcement system, and conducts stress analysis with reinforcement thickness, reinforcement range, reinforcement form, and reinforcement height as parameters to determine the optimal scheme of the reinforcement system. Based on the calculation results, a theoretical formula for the maximum principal stress and maximum deflection of the reinforcement system is proposed. To verify the feasibility of the plan, a reinforcement design was carried out on an existing beam, and it was found that the bending bearing capacity of the RC beam increased by 21%; the high tensile strength of UHPC and the addition of steel fibers have a good limiting effect on cracks; The steel plate of the reinforcement system can be used as a template, reducing construction costs and having good economy.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368089","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 : 2024-03-29DOI: 10.24425/ace.2024.148912
Renata Pigoń
The paper presents an analysis of a 100-meter wind measurement guyed mast located in the north-western part of the United States, in the state of Oregon. Using the RFEM software [1], the influence of the wind on the mast was analyzed according to the guidelines of two standards: American TIA-222-H [2] and European EN 1993-3-1 [3]. The purpose of this work is to show the differences between the results of static computations of the mast in terms of the considered standards. Due to the limited content of the work, the icing load on the structure was ignored in the analysis and the focus was on determining the response of the mast only in terms of wind action. The author tried to describe the differences in this respect between the standard guidelines [2] and [3]. The comments and conclusions regarding the analysis of guyed masts presented in the article have some practical aspects and can be used in design practice.
{"title":"Comparative analysis of guyed lattice mast computations in terms of American and European standard","authors":"Renata Pigoń","doi":"10.24425/ace.2024.148912","DOIUrl":"https://doi.org/10.24425/ace.2024.148912","url":null,"abstract":"The paper presents an analysis of a 100-meter wind measurement guyed mast located in the north-western part of the United States, in the state of Oregon. Using the RFEM software [1], the influence of the wind on the mast was analyzed according to the guidelines of two standards: American TIA-222-H [2] and European EN 1993-3-1 [3]. The purpose of this work is to show the differences between the results of static computations of the mast in terms of the considered standards. Due to the limited content of the work, the icing load on the structure was ignored in the analysis and the focus was on determining the response of the mast only in terms of wind action. The author tried to describe the differences in this respect between the standard guidelines [2] and [3]. The comments and conclusions regarding the analysis of guyed masts presented in the article have some practical aspects and can be used in design practice.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140365844","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 : 2024-03-29DOI: 10.24425/ace.2024.148909
Alina Maciejewska, J. Sobieraj, Łukasz Kuzak
Biologically active areas play an extremely important role in the structure of a city and increasing their coverage, especially in large urban centres, is an activity with a number of advantages. This article compares, in terms of green spaces, two European cities of similar size – Warsaw (517.2 km2) and Oslo (454 km2). Both cities are capitals of their respective countries but implement different spatial policies in the scope of the Green Deal. In Warsaw, many industrial and post-industrial areas still exist and simultaneously urban green areas are decreasing year by year. In Oslo, a strategy based on deindustrialisation of the city and possible maximum use of urban greenery and public spaces is implemented. The research described in this article involved analysing the coverage of the analysed cities and their districts with biologically active area and then checking the correlation with other indicators that can be affected by this coverage. These included data on the incidence of the most common diseases among residents, the attractiveness of living for the elderly and families with children, as well as air and soil pollution and the occurrence of negative effects of climate change. The correlation of urban space use in terms of the presence of industrial land in relation to currently existing green spaces in the districts concerned was subsequently determined.
{"title":"Analysis of greenery coverage of the area of the City ofWarsaw on the quality of life of residents on the basis of spatial and statistical data","authors":"Alina Maciejewska, J. Sobieraj, Łukasz Kuzak","doi":"10.24425/ace.2024.148909","DOIUrl":"https://doi.org/10.24425/ace.2024.148909","url":null,"abstract":"Biologically active areas play an extremely important role in the structure of a city and increasing their coverage, especially in large urban centres, is an activity with a number of advantages. This article compares, in terms of green spaces, two European cities of similar size – Warsaw (517.2 km2) and Oslo (454 km2). Both cities are capitals of their respective countries but implement different spatial policies in the scope of the Green Deal. In Warsaw, many industrial and post-industrial areas still exist and simultaneously urban green areas are decreasing year by year. In Oslo, a strategy based on deindustrialisation of the city and possible maximum use of urban greenery and public spaces is implemented. The research described in this article involved analysing the coverage of the analysed cities and their districts with biologically active area and then checking the correlation with other indicators that can be affected by this coverage. These included data on the incidence of the most common diseases among residents, the attractiveness of living for the elderly and families with children, as well as air and soil pollution and the occurrence of negative effects of climate change. The correlation of urban space use in terms of the presence of industrial land in relation to currently existing green spaces in the districts concerned was subsequently determined.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368942","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 : 2024-03-29DOI: 10.24425/ace.2024.148926
Yuan Fang, Lei Lv, Yuqiang Gao, Zhongqiu Fu
Buckling restrained brace is an important structure for improving the seismic resistance of structures. Conducting research on new types of buckling restrained brace can improve the seismic performance and reliability of buckling resistant support. Four different types of buckling restrained braces specimens were designed and manufactured: cross-shaped square steel pipe members, cross-shaped round steel pipe members, cross-shaped carbon fiber members, and in-line carbon fiber members. By conducting quasi-static tests, the force displacement hysteresis curves, skeleton curves, stiffness degradation, equivalent viscous damping coefficient, and energy dissipation ratio of four different types of buckling restrained brace were analyzed. The research results showed that all four buckling restrained brace specimens have good hysteresis performance. The load-bearing capacity and energy consumption performance of the three specimens of square steel pipe, round steel pipe and carbon fiber with the same core unit are the same, but the inline type is worse than the cross type. The core unit specimen with a width of 80 mm is about 60% higher in bearing capacity and energy consumption than a specimen with a width of 50 mm. The core unit of some specimens undergoes multi-wave buckling. For carbon fiber specimens, the CFRP is prone to breakage due to the lateral thrust of the restraining unit. Therefore, steel hoop or stirrup should be added to the end to improve the restraint effect when designing and manufacturing.
{"title":"Experimental of buckling restrained brace hysteretic performance with carbon fiber wrapped in concrete","authors":"Yuan Fang, Lei Lv, Yuqiang Gao, Zhongqiu Fu","doi":"10.24425/ace.2024.148926","DOIUrl":"https://doi.org/10.24425/ace.2024.148926","url":null,"abstract":"Buckling restrained brace is an important structure for improving the seismic resistance of structures. Conducting research on new types of buckling restrained brace can improve the seismic performance and reliability of buckling resistant support. Four different types of buckling restrained braces specimens were designed and manufactured: cross-shaped square steel pipe members, cross-shaped round steel pipe members, cross-shaped carbon fiber members, and in-line carbon fiber members. By conducting quasi-static tests, the force displacement hysteresis curves, skeleton curves, stiffness degradation, equivalent viscous damping coefficient, and energy dissipation ratio of four different types of buckling restrained brace were analyzed. The research results showed that all four buckling restrained brace specimens have good hysteresis performance. The load-bearing capacity and energy consumption performance of the three specimens of square steel pipe, round steel pipe and carbon fiber with the same core unit are the same, but the inline type is worse than the cross type. The core unit specimen with a width of 80 mm is about 60% higher in bearing capacity and energy consumption than a specimen with a width of 50 mm. The core unit of some specimens undergoes multi-wave buckling. For carbon fiber specimens, the CFRP is prone to breakage due to the lateral thrust of the restraining unit. Therefore, steel hoop or stirrup should be added to the end to improve the restraint effect when designing and manufacturing.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368703","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 : 2024-03-29DOI: 10.24425/ace.2024.148932
Hong Chai, Jun Guo
In promoting the construction of prefabricated residential buildings in Yunnan villages and towns, the use of precast concrete elements is unstoppable. Due to the dense arrangement of steel bars at the joints of precast concrete elements, collisions are prone to occur, which can affect the stress of the components and even pose certain safety hazards for the entire construction project. Because the commonly used the steel bar obstacle avoidance method based on building information modeling has low adaptation rate and cannot change the trajectory of the steel bar to avoid collision, a multi-agent reinforcement learning-based model integrating building information modeling is proposed to solve the steel bar collision in reinforced concrete frame. The experimental results show that the probability of obstacle avoidance of the proposed model in three typical beam-column joints is 98.45%, 98.62% and 98.39% respectively, which is 5.16%, 12.81% and 17.50% higher than that of the building information modeling. In the collision-free path design of the same object, the research on the path design of different types of precast concrete elements takes about 3–4 minutes, which is far less than the time spent by experienced structural engineers on collision-free path modeling. The experimental results indicate that the model constructed by the research institute has good performance and has certain reference significance.
{"title":"Design optimization of obstacle avoidance of intelligent building the steel bar by integrating reinforcement learning and BIM technology","authors":"Hong Chai, Jun Guo","doi":"10.24425/ace.2024.148932","DOIUrl":"https://doi.org/10.24425/ace.2024.148932","url":null,"abstract":"In promoting the construction of prefabricated residential buildings in Yunnan villages and towns, the use of precast concrete elements is unstoppable. Due to the dense arrangement of steel bars at the joints of precast concrete elements, collisions are prone to occur, which can affect the stress of the components and even pose certain safety hazards for the entire construction project. Because the commonly used the steel bar obstacle avoidance method based on building information modeling has low adaptation rate and cannot change the trajectory of the steel bar to avoid collision, a multi-agent reinforcement learning-based model integrating building information modeling is proposed to solve the steel bar collision in reinforced concrete frame. The experimental results show that the probability of obstacle avoidance of the proposed model in three typical beam-column joints is 98.45%, 98.62% and 98.39% respectively, which is 5.16%, 12.81% and 17.50% higher than that of the building information modeling. In the collision-free path design of the same object, the research on the path design of different types of precast concrete elements takes about 3–4 minutes, which is far less than the time spent by experienced structural engineers on collision-free path modeling. The experimental results indicate that the model constructed by the research institute has good performance and has certain reference significance.","PeriodicalId":45753,"journal":{"name":"Archives of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366736","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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