Pub Date : 2023-12-25DOI: 10.3390/buildings14010067
Peiwen Shen, Yue Chen, Song Ma, Yong Yan
The concrete-filled steel tubular (CFST) arch bridge has achieved significant development in recent years due to its unique mechanical performance and technical advantages. However, due to the lagging theoretical research compared to engineering practice, many problems have been exposed in the existing bridges, resulting in adverse social impacts and enormous economic losses. With the increasing prominence of safety issues in CFST arch bridges, it is necessary to assess their safety condition in service. This paper establishes a safety assessment index system for CFST arch bridges using the fuzzy analytic hierarchy process (AHP) based on an exponential scale. The assessment method proposed includes the following main points: (1) Bridge safety assessment is closely related to the load-bearing capacity of components. This study proposes an assessment index that comprehensively considers both the defect conditions and the design load-bearing capacity of components for the safety assessment. (2) The exponential scale method is introduced to safety assessment for the first time, and the AHP based on an exponential scale is applied to calculate the component weights. (3) Considering the specific structural characteristics of CFST arch bridges, this study provides a detailed division of component types and calculates the component weights. By combining the component assessment indexes, a comprehensive safety assessment index system is established, and a safety assessment method for CFST arch bridges is proposed. (4) Taking the Jiantiao Bridge in Zhejiang Province as an engineering case, the load-bearing capacity of components is calculated using finite element software ANSYS 19.1. Based on the established safety assessment index system, the safety of the bridge is assessed by integrating the inspection results. (5) Software for the safety assessment of a CFST arch bridge is developed using Visual Basic, and the assessment results align well with the actual condition of the bridge.
{"title":"Safety Assessment Method of Concrete-Filled Steel Tubular Arch Bridge by Fuzzy Analytic Hierarchy Process","authors":"Peiwen Shen, Yue Chen, Song Ma, Yong Yan","doi":"10.3390/buildings14010067","DOIUrl":"https://doi.org/10.3390/buildings14010067","url":null,"abstract":"The concrete-filled steel tubular (CFST) arch bridge has achieved significant development in recent years due to its unique mechanical performance and technical advantages. However, due to the lagging theoretical research compared to engineering practice, many problems have been exposed in the existing bridges, resulting in adverse social impacts and enormous economic losses. With the increasing prominence of safety issues in CFST arch bridges, it is necessary to assess their safety condition in service. This paper establishes a safety assessment index system for CFST arch bridges using the fuzzy analytic hierarchy process (AHP) based on an exponential scale. The assessment method proposed includes the following main points: (1) Bridge safety assessment is closely related to the load-bearing capacity of components. This study proposes an assessment index that comprehensively considers both the defect conditions and the design load-bearing capacity of components for the safety assessment. (2) The exponential scale method is introduced to safety assessment for the first time, and the AHP based on an exponential scale is applied to calculate the component weights. (3) Considering the specific structural characteristics of CFST arch bridges, this study provides a detailed division of component types and calculates the component weights. By combining the component assessment indexes, a comprehensive safety assessment index system is established, and a safety assessment method for CFST arch bridges is proposed. (4) Taking the Jiantiao Bridge in Zhejiang Province as an engineering case, the load-bearing capacity of components is calculated using finite element software ANSYS 19.1. Based on the established safety assessment index system, the safety of the bridge is assessed by integrating the inspection results. (5) Software for the safety assessment of a CFST arch bridge is developed using Visual Basic, and the assessment results align well with the actual condition of the bridge.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"14 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139158787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.3390/buildings14010065
Laixiu Cheng, Junfeng Cheng
Metal roof systems were widely utilized in various important buildings; however, cases of wind damage were often observed. In this paper, wind uplift tests of standing seam aluminum magnesium manganese and continuous welded stainless-steel roof systems were conducted, and the wind resistance bearing capacity and mechanical properties of key joints in the two roof systems were compared and analyzed. Strain gauges and displacement sensors were arranged at different structural layers and key nodes of the roof system to compare and analyze the stress and displacement changes. The results showed that the wind resistance capacity of the continuous welded stainless-steel roof system was more than 25% higher than that of the standing seam aluminum magnesium manganese roof system. The stress and displacement of the roof system gradually increased with the increase in wind load. Obvious differences in stress at different positions of the two roof systems were identified. The stress at the roof panel of the roof system was greater than that of other structural layers, and the maximum displacement of the roof panel in the elastic stage could reach more than 97.5 mm. The fitting coefficient between the test and the finite element was 0.976, and the ultimate bearing capacity of Specimen B was 479.64 MPa. The research results of this paper can provide some data support and reference for engineering design and applications.
金属屋顶系统被广泛应用于各种重要建筑中，但经常出现风灾。本文对立缝铝镁锰屋面系统和连续焊接不锈钢屋面系统进行了抗风翘起试验，对比分析了两种屋面系统的抗风承载力和关键连接处的力学性能。在屋面系统的不同结构层和关键节点上布置了应变仪和位移传感器，以比较和分析应力和位移的变化。结果表明，连续焊接不锈钢屋面系统的抗风能力比立缝铝镁锰屋面系统高出 25% 以上。随着风荷载的增加，屋面系统的应力和位移逐渐增大。两种屋面系统不同位置的应力存在明显差异。屋面系统屋面板处的应力大于其他结构层，屋面板在弹性阶段的最大位移可达 97.5 mm 以上。试验与有限元的拟合系数为 0.976，试样 B 的极限承载力为 479.64 MPa。本文的研究成果可为工程设计和应用提供一定的数据支持和参考。
{"title":"Experimental Study on Static Wind Uplift Resistance of Roofing Systems","authors":"Laixiu Cheng, Junfeng Cheng","doi":"10.3390/buildings14010065","DOIUrl":"https://doi.org/10.3390/buildings14010065","url":null,"abstract":"Metal roof systems were widely utilized in various important buildings; however, cases of wind damage were often observed. In this paper, wind uplift tests of standing seam aluminum magnesium manganese and continuous welded stainless-steel roof systems were conducted, and the wind resistance bearing capacity and mechanical properties of key joints in the two roof systems were compared and analyzed. Strain gauges and displacement sensors were arranged at different structural layers and key nodes of the roof system to compare and analyze the stress and displacement changes. The results showed that the wind resistance capacity of the continuous welded stainless-steel roof system was more than 25% higher than that of the standing seam aluminum magnesium manganese roof system. The stress and displacement of the roof system gradually increased with the increase in wind load. Obvious differences in stress at different positions of the two roof systems were identified. The stress at the roof panel of the roof system was greater than that of other structural layers, and the maximum displacement of the roof panel in the elastic stage could reach more than 97.5 mm. The fitting coefficient between the test and the finite element was 0.976, and the ultimate bearing capacity of Specimen B was 479.64 MPa. The research results of this paper can provide some data support and reference for engineering design and applications.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"5 4","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139157889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010057
S. Khusru, David P. Thambiratnam, Mohamed Elchalakani, S. Fawzia
Rubberised concrete, utilised as infill material within single- or double-skin confinements, has emerged as a sustainable solution, offering improved ductility in structures. Past studies have indicated promising results regarding the axial response of hybrid columns comprising filament wound exterior tubes, rubberised concrete infill, and steel interior tubes. This paper investigates the response of such hybrid columns under eccentric compression using validated numerical techniques. An extensive parametric study is conducted to explore the effects of load eccentricity, rubber percentage, concrete strength, and steel tube strength. Results show that despite credible increases in rubber percentage and load eccentricity, the columns have reasonably good performance. The findings facilitate the prediction of the eccentric behaviour of these hybrid columns across varying rubber percentages, confirming its viability for practical applications under realistic eccentric load conditions. The results further affirm the suitability of this hybrid column in scenarios that necessitate higher ductility.
{"title":"Behaviour of Slender Hybrid Rubberised Concrete Double Skin Tubular Columns under Eccentric Loading","authors":"S. Khusru, David P. Thambiratnam, Mohamed Elchalakani, S. Fawzia","doi":"10.3390/buildings14010057","DOIUrl":"https://doi.org/10.3390/buildings14010057","url":null,"abstract":"Rubberised concrete, utilised as infill material within single- or double-skin confinements, has emerged as a sustainable solution, offering improved ductility in structures. Past studies have indicated promising results regarding the axial response of hybrid columns comprising filament wound exterior tubes, rubberised concrete infill, and steel interior tubes. This paper investigates the response of such hybrid columns under eccentric compression using validated numerical techniques. An extensive parametric study is conducted to explore the effects of load eccentricity, rubber percentage, concrete strength, and steel tube strength. Results show that despite credible increases in rubber percentage and load eccentricity, the columns have reasonably good performance. The findings facilitate the prediction of the eccentric behaviour of these hybrid columns across varying rubber percentages, confirming its viability for practical applications under realistic eccentric load conditions. The results further affirm the suitability of this hybrid column in scenarios that necessitate higher ductility.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"1983 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010056
Yi Shen, Shuangchi Sun, Wei Sun, Long Zhou, Zhongkai Huang
This study aims to investigate the factors and consequences of gas deflagration accidents in metro shield tunnels based on on-site investigation and numerical analysis. We built a numerical model and detection process for an underground shield tunnel subjected to an internal explosion from an actual accident. The tunnel geometry under consideration is the same as that used for the metro line. Concerning the limitations of research on the failure and recovery mechanism of shield segmental linings under the action of internal explosion load, an explosion accident of a shield segmental lining under construction caused by the shield tunneling machine destroying natural gas pipelines was discussed, in which the structure failure characteristics during the explosion and the structure repair method after the explosion were investigated. An interval repair scheme was proposed, which provides experience for the treatment of similar engineering accidents. To investigate the gas explosion within the tunnel during the accident, the finite element software Ansys LS-DYNA with the arbitrary Lagrangian–Eulerian (ALE) technique was employed to simulate the explosion scenario. Dynamic analyses were carried out to reproduce the blast scenario. The stress distribution within the segmental lining as well as the lining’s deformation were calculated. The potential applications of the treatment and planning of comparable engineering mishaps were discussed in the study.
{"title":"Understanding the Factors and Consequences of Gas Deflagration Accident in Metro Shield Tunnel: Site Investigation and Numerical Analysis","authors":"Yi Shen, Shuangchi Sun, Wei Sun, Long Zhou, Zhongkai Huang","doi":"10.3390/buildings14010056","DOIUrl":"https://doi.org/10.3390/buildings14010056","url":null,"abstract":"This study aims to investigate the factors and consequences of gas deflagration accidents in metro shield tunnels based on on-site investigation and numerical analysis. We built a numerical model and detection process for an underground shield tunnel subjected to an internal explosion from an actual accident. The tunnel geometry under consideration is the same as that used for the metro line. Concerning the limitations of research on the failure and recovery mechanism of shield segmental linings under the action of internal explosion load, an explosion accident of a shield segmental lining under construction caused by the shield tunneling machine destroying natural gas pipelines was discussed, in which the structure failure characteristics during the explosion and the structure repair method after the explosion were investigated. An interval repair scheme was proposed, which provides experience for the treatment of similar engineering accidents. To investigate the gas explosion within the tunnel during the accident, the finite element software Ansys LS-DYNA with the arbitrary Lagrangian–Eulerian (ALE) technique was employed to simulate the explosion scenario. Dynamic analyses were carried out to reproduce the blast scenario. The stress distribution within the segmental lining as well as the lining’s deformation were calculated. The potential applications of the treatment and planning of comparable engineering mishaps were discussed in the study.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"506 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010055
Yachao Tang, Hongnan Li
An innovative type of precast braced concrete shear (PBCS) wall has been tested and verified to have comparable shear resistances relative to conventional cast-in-place reinforced concrete (RC) shear walls. The triangular or rectangular embedded expanded polystyrene (EPS) boards in PBCS wall panels can not only considerably reduce concrete use but also reduce the structural weight. To understand the functions of EPS boards in more depth, this paper investigates the effects of the thickness ratio of different shapes of EPS on the hysteretic behaviors of PBCS walls with various shear span ratios (SSRs). The finite element (FE) models of PBCS walls based on the multi-layer shell element are developed and verified to be sufficiently accurate in comparison with the experimental results. The analysis results indicate that the bearing capacity, lateral stiffness and ductility of PBCS walls show a downward trend with the increase in the thickness ratio of EPS boards. The rectangular EPS board has a more pronounced effect on weight reduction as well as concrete use reduction compared to the triangular EPS board under the same thickness ratio. The formulations regarding the bearing capacity are developed and show good agreement with the numerical results. The thickness ratio limit for PBCS walls to satisfy the ductility requirement is addressed. This investigation not only provides insight into the cyclic behavior of PBCS walls with varied thickness ratios but also demonstrates the potential applicability of PBCS walls in precast concrete (PC) structures for both thermal insulation and earthquake resistance purposes.
{"title":"Effects of Embedded Expanded Polystyrene Boards on the Hysteretic Behavior of Innovative Precast Braced Concrete Shear Walls","authors":"Yachao Tang, Hongnan Li","doi":"10.3390/buildings14010055","DOIUrl":"https://doi.org/10.3390/buildings14010055","url":null,"abstract":"An innovative type of precast braced concrete shear (PBCS) wall has been tested and verified to have comparable shear resistances relative to conventional cast-in-place reinforced concrete (RC) shear walls. The triangular or rectangular embedded expanded polystyrene (EPS) boards in PBCS wall panels can not only considerably reduce concrete use but also reduce the structural weight. To understand the functions of EPS boards in more depth, this paper investigates the effects of the thickness ratio of different shapes of EPS on the hysteretic behaviors of PBCS walls with various shear span ratios (SSRs). The finite element (FE) models of PBCS walls based on the multi-layer shell element are developed and verified to be sufficiently accurate in comparison with the experimental results. The analysis results indicate that the bearing capacity, lateral stiffness and ductility of PBCS walls show a downward trend with the increase in the thickness ratio of EPS boards. The rectangular EPS board has a more pronounced effect on weight reduction as well as concrete use reduction compared to the triangular EPS board under the same thickness ratio. The formulations regarding the bearing capacity are developed and show good agreement with the numerical results. The thickness ratio limit for PBCS walls to satisfy the ductility requirement is addressed. This investigation not only provides insight into the cyclic behavior of PBCS walls with varied thickness ratios but also demonstrates the potential applicability of PBCS walls in precast concrete (PC) structures for both thermal insulation and earthquake resistance purposes.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"2012 18","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Swivel bridge construction (SBC) technology has significant advantages in building bridges that span existing railway lines (ERLs), but it also entails complex risks from ‘skylight’ windows and railway boundaries. A notable challenge is the relationships and interdependencies among these risks, which collectively increase safety hazards through mutual influence. Prior research has typically focused on mitigating the risks inherent in particular tasks or operations, with less emphasis on the risks from interdependencies. A novel framework was developed to explore this research gap by integrating fuzzy logic, interpretive structural modeling (ISM) and the cross-impact matrix multiplication applied to classification (MICMAC) approach (Fuzzy-ISM-MICMAC) to investigate the relationships and interdependencies among the risks of SBC spanning ERLs and the critical points of risk control. Furthermore, the data collected from a literature review, a case analysis and expert interviews resulted in 28 risk factors. Then, the application of ISM distilled complex risk relationships into a clear, multilevel hierarchy, accurately illustrating the complex interrelationships among risk factors. Combined with MICMAC analysis, the research findings indicate that preliminary works such as the selection of construction technology, scheme design, construction rehearsal and the provision of safety facilities are essential for preventing risks in SBC spanning ERLs. We applied these findings to the double T-structure swivel construction of the Xiaojizhuang Bridge, where its practicality and efficiency were thoroughly tested and validated. This research’s critical contribution is identifying, clarifying and visualizing the interrelationships of the complex risk factors of SBC spanning ERLs and providing specific solutions for safety management in similar bridge construction projects. The research results and risk control recommendations offer valuable insights for managing other swivel bridge construction risks.
{"title":"Application of Fuzzy-ISM-MICMAC in the Risk Analysis Affecting Swivel Bridge Construction Spanning Existing Railway Lines: A Case Study","authors":"Chunyan Peng, Jiquan Wang, Huihua Chen, Runxi Tang","doi":"10.3390/buildings14010052","DOIUrl":"https://doi.org/10.3390/buildings14010052","url":null,"abstract":"Swivel bridge construction (SBC) technology has significant advantages in building bridges that span existing railway lines (ERLs), but it also entails complex risks from ‘skylight’ windows and railway boundaries. A notable challenge is the relationships and interdependencies among these risks, which collectively increase safety hazards through mutual influence. Prior research has typically focused on mitigating the risks inherent in particular tasks or operations, with less emphasis on the risks from interdependencies. A novel framework was developed to explore this research gap by integrating fuzzy logic, interpretive structural modeling (ISM) and the cross-impact matrix multiplication applied to classification (MICMAC) approach (Fuzzy-ISM-MICMAC) to investigate the relationships and interdependencies among the risks of SBC spanning ERLs and the critical points of risk control. Furthermore, the data collected from a literature review, a case analysis and expert interviews resulted in 28 risk factors. Then, the application of ISM distilled complex risk relationships into a clear, multilevel hierarchy, accurately illustrating the complex interrelationships among risk factors. Combined with MICMAC analysis, the research findings indicate that preliminary works such as the selection of construction technology, scheme design, construction rehearsal and the provision of safety facilities are essential for preventing risks in SBC spanning ERLs. We applied these findings to the double T-structure swivel construction of the Xiaojizhuang Bridge, where its practicality and efficiency were thoroughly tested and validated. This research’s critical contribution is identifying, clarifying and visualizing the interrelationships of the complex risk factors of SBC spanning ERLs and providing specific solutions for safety management in similar bridge construction projects. The research results and risk control recommendations offer valuable insights for managing other swivel bridge construction risks.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"566 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010060
Nafiseh Bigonah, R. Khaksar, A. M. Fathollahi-Fard, M. Gheibi, S. Wacławek, R. Moezzi
The seismic performance of diaphragm walls adjacent to tunnels plays a pivotal role in ensuring the stability of underground infrastructure. This article presents an extensive investigation into the seismic behavior of such diaphragm walls through advanced two-dimensional (2D) numerical modeling. The primary objective is to establish the accuracy and reliability of the numerical model by comparing its results with a reference case history from Tianjin, China. Following successful validation, the study employs rigorous two-dimensional (2D) numerical analyses to examine the response of the diaphragm wall to seismic events while considering crucial factors. These factors encompass the dynamics of pore water pressure, the diverse acceleration histories of earthquakes, varying tunnel positions, and their combined influence on the horizontal displacement of the wall. From our findings, we can conclude that earthquake duration has a more substantial impact on displacement and wall deformation compared to peak ground acceleration (PGA). Longer earthquake durations are associated with greater displacement. In dynamic analyses, the presence of water diminishes soil displacement and concentrates plastic deformation points. The distance between the tunnel and the diaphragm wall significantly affects wall displacement and deformation. The effective distance is approximately 10 m. Our findings can inform better design and construction practices to enhance the stability of underground infrastructure in seismically active regions.
{"title":"Seismic Stability and Sustainable Performance of Diaphragm Walls Adjacent to Tunnels: Insights from 2D Numerical Modeling and Key Factors","authors":"Nafiseh Bigonah, R. Khaksar, A. M. Fathollahi-Fard, M. Gheibi, S. Wacławek, R. Moezzi","doi":"10.3390/buildings14010060","DOIUrl":"https://doi.org/10.3390/buildings14010060","url":null,"abstract":"The seismic performance of diaphragm walls adjacent to tunnels plays a pivotal role in ensuring the stability of underground infrastructure. This article presents an extensive investigation into the seismic behavior of such diaphragm walls through advanced two-dimensional (2D) numerical modeling. The primary objective is to establish the accuracy and reliability of the numerical model by comparing its results with a reference case history from Tianjin, China. Following successful validation, the study employs rigorous two-dimensional (2D) numerical analyses to examine the response of the diaphragm wall to seismic events while considering crucial factors. These factors encompass the dynamics of pore water pressure, the diverse acceleration histories of earthquakes, varying tunnel positions, and their combined influence on the horizontal displacement of the wall. From our findings, we can conclude that earthquake duration has a more substantial impact on displacement and wall deformation compared to peak ground acceleration (PGA). Longer earthquake durations are associated with greater displacement. In dynamic analyses, the presence of water diminishes soil displacement and concentrates plastic deformation points. The distance between the tunnel and the diaphragm wall significantly affects wall displacement and deformation. The effective distance is approximately 10 m. Our findings can inform better design and construction practices to enhance the stability of underground infrastructure in seismically active regions.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"2017 45","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139159981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010058
Xupeng Sun, Dedong Guo, Jin Li, Zhen Liu, Meng Xu, Qinshuai Hu, Qi Xu, Shihua Yang
This study investigates the application of foam asphalt (FA) to enhance the compaction effectiveness of a hot in-place recycling asphalt mixture (HIR-AM) during the HIR process of old road surfaces. Initially, the process parameters for FA preparation were determined through expansion-rate and half-life tests. Subsequently, the study focused on evaluating the impact of FA on the compaction quality of HIR-AM. Performance assessments were conducted through rutting tests, low-temperature bending tests, Hamburg wheel tracking tests, dynamic modulus analyses, and various other experiments to evaluate the road performance of HIR-FAM. Finally, the research findings were validated through practical engineering applications, and the construction process for HIR-FAM was summarized. The research results reveal that the optimal foaming temperature for SBS asphalt is 170 °C, with an ideal water content of 1.7%. Under the same compaction temperature, HIR-FAM demonstrated a significant reduction in void content, ranging from 3.8% to 21.2% compared to HIR-AM. Moreover, a higher proportion of FA usage resulted in a more substantial decrease in void content. Compared to HIR-AM, HIR-FAM exhibited notable improvements, including an 11.6% increase in dynamic stability, a 13.4% enhancement in bending strength, a 13.3% increase in maximum bending strain, an 8.1% improvement in residual stability, and an 8.5% boost in freeze–thaw splitting strength. Furthermore, HIR-FAM demonstrated superior water-thermal stability and resistance to low-frequency loads. Paving a test road verified that the adoption of foam asphalt in thermal recycling led to a compaction density increase of over 0.79% compared to traditional in situ thermal recycling sections, with improved compaction uniformity.
{"title":"Compaction Characteristics of a Foam Asphalt Hot In-Place Recycling Asphalt Mixture","authors":"Xupeng Sun, Dedong Guo, Jin Li, Zhen Liu, Meng Xu, Qinshuai Hu, Qi Xu, Shihua Yang","doi":"10.3390/buildings14010058","DOIUrl":"https://doi.org/10.3390/buildings14010058","url":null,"abstract":"This study investigates the application of foam asphalt (FA) to enhance the compaction effectiveness of a hot in-place recycling asphalt mixture (HIR-AM) during the HIR process of old road surfaces. Initially, the process parameters for FA preparation were determined through expansion-rate and half-life tests. Subsequently, the study focused on evaluating the impact of FA on the compaction quality of HIR-AM. Performance assessments were conducted through rutting tests, low-temperature bending tests, Hamburg wheel tracking tests, dynamic modulus analyses, and various other experiments to evaluate the road performance of HIR-FAM. Finally, the research findings were validated through practical engineering applications, and the construction process for HIR-FAM was summarized. The research results reveal that the optimal foaming temperature for SBS asphalt is 170 °C, with an ideal water content of 1.7%. Under the same compaction temperature, HIR-FAM demonstrated a significant reduction in void content, ranging from 3.8% to 21.2% compared to HIR-AM. Moreover, a higher proportion of FA usage resulted in a more substantial decrease in void content. Compared to HIR-AM, HIR-FAM exhibited notable improvements, including an 11.6% increase in dynamic stability, a 13.4% enhancement in bending strength, a 13.3% increase in maximum bending strain, an 8.1% improvement in residual stability, and an 8.5% boost in freeze–thaw splitting strength. Furthermore, HIR-FAM demonstrated superior water-thermal stability and resistance to low-frequency loads. Paving a test road verified that the adoption of foam asphalt in thermal recycling led to a compaction density increase of over 0.79% compared to traditional in situ thermal recycling sections, with improved compaction uniformity.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"2003 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010053
Jiyoung Eum, Seunghwan Park, Hyun-Jung Choi
A building-integrated photovoltaic (BIPV) system produces power using photovoltaic (PV) modules as building exterior materials, whose architectural performance serves the same functions as those of existing building materials. Most relevant studies targeted general PV modules used in the building-mounted and -attached types. This study aims to integrate the building elevation-type BIPV system and exterior materials to secure both exterior material performance and PV electrical performance by embedding a power optimization device in an integrated system of BIPV modules and exterior materials. Thus, the advantages of economy, safety, aesthetics, and ease of maintenance can be achieved. In this study, experiments were conducted on elevation-type BIPV modules with and without a power optimizer, that is, a DC/DC converter, under various shade conditions, and the power loss rate of the BIPV system was analyzed. The power optimizer-equipped BIPV system was experimentally observed to have a PV power-loss rate approximately 2–3 times lower than that of the BIPV system without a power optimizer when the shade ratio of one module was approximately 10–75%. This exterior material-integrated BIPV-specific power optimization device reduces dependence on fossil fuels for power production and improves energy sustainability, contributing to the spread of zero-energy buildings and carbon neutrality.
{"title":"Effects of Power Optimizer Application in a Building-Integrated Photovoltaic System According to Shade Conditions","authors":"Jiyoung Eum, Seunghwan Park, Hyun-Jung Choi","doi":"10.3390/buildings14010053","DOIUrl":"https://doi.org/10.3390/buildings14010053","url":null,"abstract":"A building-integrated photovoltaic (BIPV) system produces power using photovoltaic (PV) modules as building exterior materials, whose architectural performance serves the same functions as those of existing building materials. Most relevant studies targeted general PV modules used in the building-mounted and -attached types. This study aims to integrate the building elevation-type BIPV system and exterior materials to secure both exterior material performance and PV electrical performance by embedding a power optimization device in an integrated system of BIPV modules and exterior materials. Thus, the advantages of economy, safety, aesthetics, and ease of maintenance can be achieved. In this study, experiments were conducted on elevation-type BIPV modules with and without a power optimizer, that is, a DC/DC converter, under various shade conditions, and the power loss rate of the BIPV system was analyzed. The power optimizer-equipped BIPV system was experimentally observed to have a PV power-loss rate approximately 2–3 times lower than that of the BIPV system without a power optimizer when the shade ratio of one module was approximately 10–75%. This exterior material-integrated BIPV-specific power optimization device reduces dependence on fossil fuels for power production and improves energy sustainability, contributing to the spread of zero-energy buildings and carbon neutrality.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"2011 31","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-24DOI: 10.3390/buildings14010051
Yun Cheng, Z. Song, Fahong Wu, Xiaoping Zhu, Wei Yuan
The deterioration of the surrounding rock at the tunnel bottom is a damage mechanics issue that occurs under disturbance load. To investigate the anisotropic characteristics of mechanical behavior and the AE response mechanism of layered sandstone, uniaxial compression tests and acoustic emission (AE) monitoring were conducted. The results show that the layer structure causes remarkable anisotropic characteristics in the wave velocities. The strain characteristics and mechanical parameters of layered sandstone exhibit obvious deterioration effects. The local strain and overall strain show a synergistic feature, with the local strain path being more complex and the deformation response being extremely sensitive. The peak stress and elastic modulus both exhibit V-type distribution rules, slowly decreasing first, then rapidly decreasing, and finally increasing rapidly, with the boundary points of the layer angle being 45° and 67.50°. The peak stress and elastic modulus show a nonlinear exponential correlation with the layer angle, and the sandstone belongs to the intermediate anisotropy level. The rupture pattern shows significant anisotropic characteristics, with the failure modes including tension failure, including tension failure I and tension failure Ⅱ, shear failure, and tension–shear composite failure. The fractal dimension shows a negative correlation with the layer deterioration effect. The AE activity exhibits a phased response characteristic to the aging deformation of layer structure. The more obvious the layer deterioration effect is, the longer the AE delay is. The AE intensity of tensile failure sandstone is generally greater than that of oblique shear failure.
{"title":"Investigating the Mechanical Deterioration Effect of Hard Sandstone Induced by Layer Structure under Uniaxial Compression","authors":"Yun Cheng, Z. Song, Fahong Wu, Xiaoping Zhu, Wei Yuan","doi":"10.3390/buildings14010051","DOIUrl":"https://doi.org/10.3390/buildings14010051","url":null,"abstract":"The deterioration of the surrounding rock at the tunnel bottom is a damage mechanics issue that occurs under disturbance load. To investigate the anisotropic characteristics of mechanical behavior and the AE response mechanism of layered sandstone, uniaxial compression tests and acoustic emission (AE) monitoring were conducted. The results show that the layer structure causes remarkable anisotropic characteristics in the wave velocities. The strain characteristics and mechanical parameters of layered sandstone exhibit obvious deterioration effects. The local strain and overall strain show a synergistic feature, with the local strain path being more complex and the deformation response being extremely sensitive. The peak stress and elastic modulus both exhibit V-type distribution rules, slowly decreasing first, then rapidly decreasing, and finally increasing rapidly, with the boundary points of the layer angle being 45° and 67.50°. The peak stress and elastic modulus show a nonlinear exponential correlation with the layer angle, and the sandstone belongs to the intermediate anisotropy level. The rupture pattern shows significant anisotropic characteristics, with the failure modes including tension failure, including tension failure I and tension failure Ⅱ, shear failure, and tension–shear composite failure. The fractal dimension shows a negative correlation with the layer deterioration effect. The AE activity exhibits a phased response characteristic to the aging deformation of layer structure. The more obvious the layer deterioration effect is, the longer the AE delay is. The AE intensity of tensile failure sandstone is generally greater than that of oblique shear failure.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"2009 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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