Pub Date : 2024-01-02DOI: 10.3390/buildings14010123
Xin Lu, Yong Liu, Xiaolong Hou, Cai Chen, Ruidan Gao
The service performance of tunnel lining is affected by crack properties and development states. In this paper, numerical simulation models were established to investigate the mechanics characteristics and safety performance for lining structures under different cracks based on the extended finite element method (XFEM). Analyze multiple quantitative factors in simulation, including changes in crack location, crack length, and crack distribution range in the lining structure. The axial force and bending moment of the preset cracks in the lining structures were first studied. The maximum safety factor attenuation rate (Dkmax) was proposed to analyze the impact of longitudinal and annular cracks on the safety performance. The axial force at the vault of the lining arch is the most significantly affected by the combined longitudinal cracks at multiple locations. When the length of a longitudinal crack increases from 1 m to 6 m, the axial force value at the crack point decreases by 33.77%, 36.15%, and 11.32%. However, the bending moment value increases by 4.47 times, 2.50 times, and 1.69 times. Under the influence of longitudinal cracks in an “arch crown + arch shoulder”, “arch crown + arch waist”, and “arch crown + arch shoulder + arch waist”, the axial force in the arch vault increased by 21.55%, decreased by 17.52%, and decreased by 13.45%. The distribution pattern of the bending moment under the influence of circumferential cracks shows convexity at the arch shoulder and arch foot, and concavity at the arch waist and side walls. The safety factor scatter curve with longitudinal cracks shows a gradual transition from a “W” shape to a “U” shape. The safety factor curve with circumferential cracks presents an approximately symmetrical wave-shaped distribution.
{"title":"Numerical Simulation of Mechanical Characteristics and Safety Performance for Pre-Cracked Tunnel Lining with the Extended Finite Element Method","authors":"Xin Lu, Yong Liu, Xiaolong Hou, Cai Chen, Ruidan Gao","doi":"10.3390/buildings14010123","DOIUrl":"https://doi.org/10.3390/buildings14010123","url":null,"abstract":"The service performance of tunnel lining is affected by crack properties and development states. In this paper, numerical simulation models were established to investigate the mechanics characteristics and safety performance for lining structures under different cracks based on the extended finite element method (XFEM). Analyze multiple quantitative factors in simulation, including changes in crack location, crack length, and crack distribution range in the lining structure. The axial force and bending moment of the preset cracks in the lining structures were first studied. The maximum safety factor attenuation rate (Dkmax) was proposed to analyze the impact of longitudinal and annular cracks on the safety performance. The axial force at the vault of the lining arch is the most significantly affected by the combined longitudinal cracks at multiple locations. When the length of a longitudinal crack increases from 1 m to 6 m, the axial force value at the crack point decreases by 33.77%, 36.15%, and 11.32%. However, the bending moment value increases by 4.47 times, 2.50 times, and 1.69 times. Under the influence of longitudinal cracks in an “arch crown + arch shoulder”, “arch crown + arch waist”, and “arch crown + arch shoulder + arch waist”, the axial force in the arch vault increased by 21.55%, decreased by 17.52%, and decreased by 13.45%. The distribution pattern of the bending moment under the influence of circumferential cracks shows convexity at the arch shoulder and arch foot, and concavity at the arch waist and side walls. The safety factor scatter curve with longitudinal cracks shows a gradual transition from a “W” shape to a “U” shape. The safety factor curve with circumferential cracks presents an approximately symmetrical wave-shaped distribution.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139452725","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 : 2024-01-02DOI: 10.3390/buildings14010116
Je-won Kim, Kyungnam Kim, Tri Ho Minh Le
This study addresses the imperative for enhancing asphalt mixtures tailored for rural pavements, focusing on optimizing RAP mixtures with styrene–butadiene–styrene (SBS)-modified asphalt binders incorporating petroleum resin and oil. Through systematic investigation, the study examines the impact of varying RAP content (25% and 50%) and two SBS-modified asphalt binder types (Type 1 and Type 2) on mechanical properties and sustainability. Laboratory tests reveal that the mix of 25% RAP + 75% Type 1 exhibits exceptional flexibility, evidenced by a high ductility value of 880 mm at 25 °C, enhancing pavement resilience. Conversely, the 50% RAP + 50% Type 2 mixture displays vulnerability to fatigue cracking, while 25% RAP + 75% Type 1 demonstrates superior resistance, with a fatigue vulnerability value of 1524 kPa. The Hamburg Wheel Tracking test highlights the influence of RAP content on rut depth, with the mix of 50% RAP + 50% Type 1 achieving the lowest rutting at 3.9 mm. Overlay test results show the mix of 25% RAP + 75% Type 2’s resilience, with the lowest load reduction at 64.5%, while the mix of 50% RAP + 50% Type 1 exhibits substantial load reduction at 82.1%. Field tests unveil differences in pavement bearing capacities, with the mix of 25% RAP + 75% Type 2 demonstrating a remarkable elastic modulus of 58.5 MPa, indicating heightened bearing capacity. The investigation underscores the significant role of SBS-modified asphalt binders with incorporated petroleum resin and oil in enhancing fatigue resistance for sustainable rural pavements.
本研究探讨了改善农村路面沥青混合料的必要性，重点是优化含有苯乙烯-丁二烯-苯乙烯（SBS）改性沥青粘结剂（含石油树脂和石油）的 RAP 混合料。该研究通过系统调查，研究了不同 RAP 含量（25% 和 50%）和两种 SBS 改性沥青胶结料类型（1 型和 2 型）对机械性能和可持续性的影响。实验室测试表明，25% RAP + 75% Type 1 的混合料具有优异的柔韧性，在 25 °C 时的延度值高达 880 mm，从而增强了路面的弹性。相反，50% RAP + 50% Type 2 混合料易出现疲劳开裂，而 25% RAP + 75% Type 1 则表现出卓越的抗压性能，疲劳易损值为 1524 kPa。汉堡车轮跟踪测试凸显了 RAP 含量对车辙深度的影响，50% RAP + 50% 1 型混合料的车辙深度最低，仅为 3.9 毫米。覆盖层测试结果表明，25% RAP + 75% Type 2 混合料具有弹性，荷载降低率最低，为 64.5%，而 50% RAP + 50% Type 1 混合料的荷载降低率则高达 82.1%。现场测试揭示了路面承载能力的差异，25% RAP + 75% Type 2 混合料的弹性模量高达 58.5 兆帕，显示出更高的承载能力。这项调查强调了加入石油树脂和石油的 SBS 改性沥青胶结料在增强可持续农村路面抗疲劳性方面的重要作用。
{"title":"Optimizing Rural Pavements with SBS-Modified Asphalt Binders and Petroleum Resin","authors":"Je-won Kim, Kyungnam Kim, Tri Ho Minh Le","doi":"10.3390/buildings14010116","DOIUrl":"https://doi.org/10.3390/buildings14010116","url":null,"abstract":"This study addresses the imperative for enhancing asphalt mixtures tailored for rural pavements, focusing on optimizing RAP mixtures with styrene–butadiene–styrene (SBS)-modified asphalt binders incorporating petroleum resin and oil. Through systematic investigation, the study examines the impact of varying RAP content (25% and 50%) and two SBS-modified asphalt binder types (Type 1 and Type 2) on mechanical properties and sustainability. Laboratory tests reveal that the mix of 25% RAP + 75% Type 1 exhibits exceptional flexibility, evidenced by a high ductility value of 880 mm at 25 °C, enhancing pavement resilience. Conversely, the 50% RAP + 50% Type 2 mixture displays vulnerability to fatigue cracking, while 25% RAP + 75% Type 1 demonstrates superior resistance, with a fatigue vulnerability value of 1524 kPa. The Hamburg Wheel Tracking test highlights the influence of RAP content on rut depth, with the mix of 50% RAP + 50% Type 1 achieving the lowest rutting at 3.9 mm. Overlay test results show the mix of 25% RAP + 75% Type 2’s resilience, with the lowest load reduction at 64.5%, while the mix of 50% RAP + 50% Type 1 exhibits substantial load reduction at 82.1%. Field tests unveil differences in pavement bearing capacities, with the mix of 25% RAP + 75% Type 2 demonstrating a remarkable elastic modulus of 58.5 MPa, indicating heightened bearing capacity. The investigation underscores the significant role of SBS-modified asphalt binders with incorporated petroleum resin and oil in enhancing fatigue resistance for sustainable rural pavements.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"56 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139452761","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 : 2024-01-01DOI: 10.3390/buildings14010115
Ik-Hyun An, Su-Hoon Park, Yong-Ho Lee, Chang-Hoon Lee, Sang-Bum Seo, Sang-Hyun Cho, Hyun-Woo Lee, S. Yook
A novel displacement ventilation system (DVS) was designed using a four-way cassette fan coil unit (FCU) and air purifiers (APs) for supplying clean air. The proposed DVS in this study involved drawing indoor air through the FCU and diffusers installed in the ceiling, controlling air temperature using the FCU, and then discharging it back into the office through the APs placed on the floor. The comparative ventilation system considered was the typical mixing ventilation system (MVS) that intakes and exhausts indoor air using diffusers installed on the ceiling. The local mean age of air was used as an index to compare indoor air quality between DVS and MVS under winter heating conditions. It was found that the DVS was more effective in improving indoor air quality in winter than the MVS. Moreover, compared to the MVS, utilizing the DVS designed in this study resulted in the advantage of a much more uniform air temperature variation in the office space. Therefore, it is anticipated that modifying the structure of an indoor space with an FCU installed in the ceiling and APs on the floor to use the DVS designed in this study would greatly assist in enhancing indoor air quality.
{"title":"Comparison of Local Mean Age of Air between Displacement Ventilation System and Mixing Ventilation System in Office Heating Conditions during Winter","authors":"Ik-Hyun An, Su-Hoon Park, Yong-Ho Lee, Chang-Hoon Lee, Sang-Bum Seo, Sang-Hyun Cho, Hyun-Woo Lee, S. Yook","doi":"10.3390/buildings14010115","DOIUrl":"https://doi.org/10.3390/buildings14010115","url":null,"abstract":"A novel displacement ventilation system (DVS) was designed using a four-way cassette fan coil unit (FCU) and air purifiers (APs) for supplying clean air. The proposed DVS in this study involved drawing indoor air through the FCU and diffusers installed in the ceiling, controlling air temperature using the FCU, and then discharging it back into the office through the APs placed on the floor. The comparative ventilation system considered was the typical mixing ventilation system (MVS) that intakes and exhausts indoor air using diffusers installed on the ceiling. The local mean age of air was used as an index to compare indoor air quality between DVS and MVS under winter heating conditions. It was found that the DVS was more effective in improving indoor air quality in winter than the MVS. Moreover, compared to the MVS, utilizing the DVS designed in this study resulted in the advantage of a much more uniform air temperature variation in the office space. Therefore, it is anticipated that modifying the structure of an indoor space with an FCU installed in the ceiling and APs on the floor to use the DVS designed in this study would greatly assist in enhancing indoor air quality.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"127 18","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139128397","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}
This paper optimizes the design of a novel large-span cable-supported steel–concrete composite floor system in a simply supported single-span, single-strut configuration, aiming for cost-effective solutions and minimal steel consumption. The optimization considers various cross-sectional dimensions, adhering to building standards and engineering practices, and is based on a non-linear programming (NLP) algorithm. Parameters of live loads ranging from 2 to 10 kN/m2 and spans from 20 to 100 m are considered. The optimization results show that cable-supported composite floors with a single strut exhibit robust economic feasibility for spans of less than 80 m and live loads under 8 kN/m2. Compared to conventional composite floors with welded I-beams, the cable-supported system offers more cost-effective cross-sections and reduces steel consumption. The savings in economically equivalent steel consumption range from 20% to 60%. Discussion on the area ratio of cables to steel beam in the optimal cross-section reveals that the secondary load-bearing system (i.e., bending of the main beam with an effective span length of L/2) may require more steel in cases of ultra-large spans. Therefore, the economical efficiency of cable-supported composite beams with multiple struts and smaller effective span lengths warrants further exploration in future studies.
{"title":"Optimal Design of a Novel Large-Span Cable-Supported Steel–Concrete Composite Floor System","authors":"Meiwen Tan, Yifan Wu, Wenhao Pan, Guoming Liu, Wei Chen","doi":"10.3390/buildings14010113","DOIUrl":"https://doi.org/10.3390/buildings14010113","url":null,"abstract":"This paper optimizes the design of a novel large-span cable-supported steel–concrete composite floor system in a simply supported single-span, single-strut configuration, aiming for cost-effective solutions and minimal steel consumption. The optimization considers various cross-sectional dimensions, adhering to building standards and engineering practices, and is based on a non-linear programming (NLP) algorithm. Parameters of live loads ranging from 2 to 10 kN/m2 and spans from 20 to 100 m are considered. The optimization results show that cable-supported composite floors with a single strut exhibit robust economic feasibility for spans of less than 80 m and live loads under 8 kN/m2. Compared to conventional composite floors with welded I-beams, the cable-supported system offers more cost-effective cross-sections and reduces steel consumption. The savings in economically equivalent steel consumption range from 20% to 60%. Discussion on the area ratio of cables to steel beam in the optimal cross-section reveals that the secondary load-bearing system (i.e., bending of the main beam with an effective span length of L/2) may require more steel in cases of ultra-large spans. Therefore, the economical efficiency of cable-supported composite beams with multiple struts and smaller effective span lengths warrants further exploration in future studies.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"105 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139133719","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 : 2023-12-31DOI: 10.3390/buildings14010111
Rongguo Zhao, Guangfei Chen, Zaihua Zhang, Wei Luo
To estimate the progressive collapse resistance capacity of a multi-column frame tube structure with an assembled truss beam composite floor (ATBCF), pushdown analysis and nonlinear dynamic analysis are conducted for such a structure using the alternate load path (ALP) method. The bearing capacities of the remaining structures under three different work conditions, which are the side middle column removal, the edge middle column removal, and the corner column removal, are individually studied, and the collapse mechanism of the remaining structures is analyzed based on the aspects of the internal force redistribution and the failure mode of the second defense line. Simultaneously, the influence of the column failure time on the dynamic response of the remaining structure and the dynamic amplification coefficient is discussed. The results indicate that the residual bearing capacity of the remaining structure following the bottom corner column removal is higher than that of the one following the side or edge middle column removal, while the latter has a stronger plastic deformation capacity. When the ALP method is adopted to operate the progressive collapse analysis, it is reasonable to take the column failure time as 0.1 times the period of the first-order vertical vibration mode of the remaining structure, and it is suitable to set the dynamic amplification coefficient as 2.0, which is the ratio of the maximum dynamic displacement to the static displacement of the remaining structure under the transient loading condition.
为了估算带装配式桁架梁复合楼板（ATBCF）的多柱框架管式结构的渐进抗倒塌能力，我们采用交替荷载路径（ALP）方法对该结构进行了推倒分析和非线性动力分析。分别研究了边中柱拆除、边中柱拆除和角柱拆除三种不同工况下剩余结构的承载力，并基于内力再分布和第二道防线的破坏模式分析了剩余结构的倒塌机理。同时，讨论了柱破坏时间对剩余结构动态响应和动态放大系数的影响。结果表明，底部角柱拆除后剩余结构的剩余承载力高于侧面或边缘中间柱拆除后的剩余结构，而后者的塑性变形能力更强。采用 ALP 方法进行渐进式坍塌分析时，将柱破坏时间取为剩余结构一阶竖向振型周期的 0.1 倍是合理的，将动态放大系数取为 2.0（即瞬态荷载条件下剩余结构最大动态位移与静态位移之比）也是合适的。
{"title":"Progressive Collapse Resistance Assessment of a Multi-Column Frame Tube Structure with an Assembled Truss Beam Composite Floor under Different Column Removal Conditions","authors":"Rongguo Zhao, Guangfei Chen, Zaihua Zhang, Wei Luo","doi":"10.3390/buildings14010111","DOIUrl":"https://doi.org/10.3390/buildings14010111","url":null,"abstract":"To estimate the progressive collapse resistance capacity of a multi-column frame tube structure with an assembled truss beam composite floor (ATBCF), pushdown analysis and nonlinear dynamic analysis are conducted for such a structure using the alternate load path (ALP) method. The bearing capacities of the remaining structures under three different work conditions, which are the side middle column removal, the edge middle column removal, and the corner column removal, are individually studied, and the collapse mechanism of the remaining structures is analyzed based on the aspects of the internal force redistribution and the failure mode of the second defense line. Simultaneously, the influence of the column failure time on the dynamic response of the remaining structure and the dynamic amplification coefficient is discussed. The results indicate that the residual bearing capacity of the remaining structure following the bottom corner column removal is higher than that of the one following the side or edge middle column removal, while the latter has a stronger plastic deformation capacity. When the ALP method is adopted to operate the progressive collapse analysis, it is reasonable to take the column failure time as 0.1 times the period of the first-order vertical vibration mode of the remaining structure, and it is suitable to set the dynamic amplification coefficient as 2.0, which is the ratio of the maximum dynamic displacement to the static displacement of the remaining structure under the transient loading condition.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"122 20","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139132773","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 : 2023-12-31DOI: 10.3390/buildings14010112
Cinthya Alvarado, Daniel Martínez-Cerna, Hernán Alvarado-Quintana
In this study, geopolymers made of metakaolin (MK), diatomite (D), and rice husk ash (RHA) were developed for ceiling thermal insulation in houses to provide protection against cold temperatures. The influence of the constituent mixing ratio and the temperature of curing on the heat conductivity and compressive strength of the geopolymer was investigated. Specimens were formed according to a 10-level mix design with three replicates and subjected to curing at 40 °C and 80 °C. Heat conductivity and compressive strength were determined in accordance with established standards. The simplex lattice method was used to obtain the response surfaces, contour plots, and tracking curves. The geopolymers under study displayed a reduction in heat conductivity and an increase in compressive strength when the curing temperature was raised. The optimal mixing ratio to achieve a balance between the compressive strength and thermal conductivity of the geopolymers investigated was 0.50 MK and 0.50 RHA. Diatomite’s thermal insulation contribution is neutralized when crystals from the geopolymer gel fill the pore volume. The mixture’s optimal results were achieved when cured at 80 °C, demonstrating a thermal conductivity of 0.10 W/m·K and a compressive strength of 5.37 MPa.
本研究开发了由偏高岭土（MK）、硅藻土（D）和稻壳灰（RHA）制成的土工聚合物，用于房屋天花板隔热，以抵御低温。研究了成分混合比例和固化温度对土工聚合物导热性和抗压强度的影响。试样按照 10 级混合设计制成，有三次重复，分别在 40 °C 和 80 °C 下固化。导热系数和抗压强度按照既定标准测定。采用简单网格法获得响应面、等值线图和跟踪曲线。当固化温度升高时，所研究的土工聚合物的导热系数降低，抗压强度升高。要在所研究的土工聚合物的抗压强度和导热系数之间取得平衡，最佳混合比例为 0.50 MK 和 0.50 RHA。当土工聚合物凝胶的晶体充满孔隙时，硅藻土的隔热作用就会被中和。混合物在 80 °C 固化时达到最佳效果，导热系数为 0.10 W/m-K，抗压强度为 5.37 MPa。
{"title":"Geopolymer Made from Kaolin, Diatomite, and Rice Husk Ash for Ceiling Thermal Insulation","authors":"Cinthya Alvarado, Daniel Martínez-Cerna, Hernán Alvarado-Quintana","doi":"10.3390/buildings14010112","DOIUrl":"https://doi.org/10.3390/buildings14010112","url":null,"abstract":"In this study, geopolymers made of metakaolin (MK), diatomite (D), and rice husk ash (RHA) were developed for ceiling thermal insulation in houses to provide protection against cold temperatures. The influence of the constituent mixing ratio and the temperature of curing on the heat conductivity and compressive strength of the geopolymer was investigated. Specimens were formed according to a 10-level mix design with three replicates and subjected to curing at 40 °C and 80 °C. Heat conductivity and compressive strength were determined in accordance with established standards. The simplex lattice method was used to obtain the response surfaces, contour plots, and tracking curves. The geopolymers under study displayed a reduction in heat conductivity and an increase in compressive strength when the curing temperature was raised. The optimal mixing ratio to achieve a balance between the compressive strength and thermal conductivity of the geopolymers investigated was 0.50 MK and 0.50 RHA. Diatomite’s thermal insulation contribution is neutralized when crystals from the geopolymer gel fill the pore volume. The mixture’s optimal results were achieved when cured at 80 °C, demonstrating a thermal conductivity of 0.10 W/m·K and a compressive strength of 5.37 MPa.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"109 44","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139134363","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 : 2023-12-31DOI: 10.3390/buildings14010108
Yiwen Liu, Chun-Huei Liu, Xiaolong Wang, Junjie Zhang, Yang Yang, Yi Wang
The current design of commercial service spaces in many communities faces issues like incoherence, irrational resource allocation, and low utilization rates. These challenges contribute to increased energy consumption in communities, hindering the overall sustainable development of cities. As a representative community space in the urban environment, the commercial space within the campus requires continuous energy input. Its energy-efficient layout aligns with the principles of sustainable development. This paper uses the university campus as a case study to examine energy-efficient commercial space layout and community practices for environmental protection. Various factors influence the layout of inter-community commercial spaces, and the parameters for measuring the layout structure are diverse, considering the large sample size. Employing machine learning and big data processing to quantify development indicators across various industries and optimize their structure, resource allocation, and energy use has emerged as a viable tool for sustainable urban planning practices. This research seeks to utilize machine learning and data-driven optimization techniques to formulate a comprehensive framework for the sustainable allocation and design of business service spaces within communities. Firstly, we conduct a comprehensive investigation, which includes data collected by applying questionnaire surveys and field research, to assess and model the factors influencing the spatial layout of commercial services on university campuses. Secondly, the AEL machine learning model is constructed by combining the analytic hierarchy process to determine subjective weights, the entropy weight method to calculate objective weights, and the Lagrange algorithm to determine comprehensive weights. Thirdly, we assess and improve the layout of commercial service spaces. Then, by training and testing the Neural Network Model, we apply cases to ensure the accuracy of the machine learning calculation results. Qualitative analysis elucidates the varying factors influencing the sustainable layout of different commercial spaces. Quantitative analysis indicates that, within university campuses, the distance between commercial service spaces and residence halls is a crucial factor in fostering a more sustainable layout. Other significant factors include their location along major student routes and proximity to teaching areas. This study makes contributions not only to the specific field of optimizing commercial service space in communities but also to the broader discourse on sustainable urban development. It advances our understanding of the complex dynamics involved in crafting urban environments that are both efficient and environmentally friendly. Beyond theoretical considerations, the study provides practical solutions and recommendations applicable to implementing tangible improvements in resource allocation. These contributions aim to foster urban environments that a
{"title":"Exploring the Layout Optimization of Commercial Service Space Affecting Energy Consumption in Communities Using Machine Learning","authors":"Yiwen Liu, Chun-Huei Liu, Xiaolong Wang, Junjie Zhang, Yang Yang, Yi Wang","doi":"10.3390/buildings14010108","DOIUrl":"https://doi.org/10.3390/buildings14010108","url":null,"abstract":"The current design of commercial service spaces in many communities faces issues like incoherence, irrational resource allocation, and low utilization rates. These challenges contribute to increased energy consumption in communities, hindering the overall sustainable development of cities. As a representative community space in the urban environment, the commercial space within the campus requires continuous energy input. Its energy-efficient layout aligns with the principles of sustainable development. This paper uses the university campus as a case study to examine energy-efficient commercial space layout and community practices for environmental protection. Various factors influence the layout of inter-community commercial spaces, and the parameters for measuring the layout structure are diverse, considering the large sample size. Employing machine learning and big data processing to quantify development indicators across various industries and optimize their structure, resource allocation, and energy use has emerged as a viable tool for sustainable urban planning practices. This research seeks to utilize machine learning and data-driven optimization techniques to formulate a comprehensive framework for the sustainable allocation and design of business service spaces within communities. Firstly, we conduct a comprehensive investigation, which includes data collected by applying questionnaire surveys and field research, to assess and model the factors influencing the spatial layout of commercial services on university campuses. Secondly, the AEL machine learning model is constructed by combining the analytic hierarchy process to determine subjective weights, the entropy weight method to calculate objective weights, and the Lagrange algorithm to determine comprehensive weights. Thirdly, we assess and improve the layout of commercial service spaces. Then, by training and testing the Neural Network Model, we apply cases to ensure the accuracy of the machine learning calculation results. Qualitative analysis elucidates the varying factors influencing the sustainable layout of different commercial spaces. Quantitative analysis indicates that, within university campuses, the distance between commercial service spaces and residence halls is a crucial factor in fostering a more sustainable layout. Other significant factors include their location along major student routes and proximity to teaching areas. This study makes contributions not only to the specific field of optimizing commercial service space in communities but also to the broader discourse on sustainable urban development. It advances our understanding of the complex dynamics involved in crafting urban environments that are both efficient and environmentally friendly. Beyond theoretical considerations, the study provides practical solutions and recommendations applicable to implementing tangible improvements in resource allocation. These contributions aim to foster urban environments that a","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"103 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139133586","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 : 2023-12-31DOI: 10.3390/buildings14010106
Sajid Mehmood, K. P. Amber, Muhammad Usman, Daniel Friedrich
Rising temperatures, increase in population, and dense urban morphology have resulted in increased cooling energy demands. The conventional degree-days method to calculate cooling energy demand considers only the sensible heat load of air and neglects the latent component. This study aims to estimate the cooling degree days based on the heat index (by considering both the sensible and latent loads) for the current and future years (2050 and 2080). Further, the ventilation load index for each of these cities has been established to unlock the impact of ventilation on the building’s total energy consumption for current and future years. The results show that heat index-based degree days have a stronger relationship with the buildings’ cooling energy consumption and, therefore, can predict the cooling energy demand of buildings with 20% higher accuracy than conventional temperature-based degree days. Analysis shows that cooling degree-days and frequency of temperature above the comfort range continue to increase in Pakistan, highlighting increased degree-days in the range from 11.0 to 41.6% by 2050 and from 28.4 to 126.5% by 2080. Prompt actions are essential to enhance the resilience of Pakistan’s national grid to meet these future cooling energy demands.
{"title":"Integrating Latent Load into the Cooling Degree Days Concept for Current and Future Weather Projections","authors":"Sajid Mehmood, K. P. Amber, Muhammad Usman, Daniel Friedrich","doi":"10.3390/buildings14010106","DOIUrl":"https://doi.org/10.3390/buildings14010106","url":null,"abstract":"Rising temperatures, increase in population, and dense urban morphology have resulted in increased cooling energy demands. The conventional degree-days method to calculate cooling energy demand considers only the sensible heat load of air and neglects the latent component. This study aims to estimate the cooling degree days based on the heat index (by considering both the sensible and latent loads) for the current and future years (2050 and 2080). Further, the ventilation load index for each of these cities has been established to unlock the impact of ventilation on the building’s total energy consumption for current and future years. The results show that heat index-based degree days have a stronger relationship with the buildings’ cooling energy consumption and, therefore, can predict the cooling energy demand of buildings with 20% higher accuracy than conventional temperature-based degree days. Analysis shows that cooling degree-days and frequency of temperature above the comfort range continue to increase in Pakistan, highlighting increased degree-days in the range from 11.0 to 41.6% by 2050 and from 28.4 to 126.5% by 2080. Prompt actions are essential to enhance the resilience of Pakistan’s national grid to meet these future cooling energy demands.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"116 42","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139135490","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 : 2023-12-31DOI: 10.3390/buildings14010110
Haowen You, Chenxu Si, Xinwen Ma, Jingmiao Shang
The glass curtain walls of post-installed elevator shafts in existing buildings can be damaged by local wind loads, and the serviceability of an elevator may be affected by excessive overall wind loads, especially in hurricane-prone areas. The overall and local wind load characteristics of elevator shafts with different arrangements (E-type, H-type, I-type) were studied using wind tunnel tests and computational fluid dynamics (CFD) numerical simulations. Firstly, high-frequency base balance wind tunnel tests of these elevator shafts with three arrangements were carried out to obtain the overall wind loads on the elevator shafts. Secondly, a CFD simulation was performed on the post-installed elevator shafts with three arrangements, obtaining the surface local wind pressure distribution of the elevator shafts under different wind directions. Finally, the wind-induced displacement responses of post-installed elevator shafts were analyzed. The results show that the aerodynamic interference of different elevator arrangements (E-type, H-type, I-type) and wind directions have significant effects on the overall local wind loads and wind-induced responses of the post-installed elevator, while the local wind loads on the area of the elevator door are less influenced by the elevator arrangement type than local wind loads on the surface and the overall wind loads of the elevator shafts. The results and conclusions may be helpful for developing the wind-resistant design of a post-installed elevator shaft.
{"title":"Overall and Local Wind Loads on Post-Installed Elevator Shaft of Existing Buildings","authors":"Haowen You, Chenxu Si, Xinwen Ma, Jingmiao Shang","doi":"10.3390/buildings14010110","DOIUrl":"https://doi.org/10.3390/buildings14010110","url":null,"abstract":"The glass curtain walls of post-installed elevator shafts in existing buildings can be damaged by local wind loads, and the serviceability of an elevator may be affected by excessive overall wind loads, especially in hurricane-prone areas. The overall and local wind load characteristics of elevator shafts with different arrangements (E-type, H-type, I-type) were studied using wind tunnel tests and computational fluid dynamics (CFD) numerical simulations. Firstly, high-frequency base balance wind tunnel tests of these elevator shafts with three arrangements were carried out to obtain the overall wind loads on the elevator shafts. Secondly, a CFD simulation was performed on the post-installed elevator shafts with three arrangements, obtaining the surface local wind pressure distribution of the elevator shafts under different wind directions. Finally, the wind-induced displacement responses of post-installed elevator shafts were analyzed. The results show that the aerodynamic interference of different elevator arrangements (E-type, H-type, I-type) and wind directions have significant effects on the overall local wind loads and wind-induced responses of the post-installed elevator, while the local wind loads on the area of the elevator door are less influenced by the elevator arrangement type than local wind loads on the surface and the overall wind loads of the elevator shafts. The results and conclusions may be helpful for developing the wind-resistant design of a post-installed elevator shaft.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"113 47","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139133492","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 : 2023-12-31DOI: 10.3390/buildings14010104
Elena Ferretti
This paper is the continuation of a previous study, which highlighted some inconsistencies in the RILEM guidelines for the interpretation of the diagonal compression test. Although improved compared to the ASTM guidelines, in fact, the RILEM guidelines underestimate the state of hydrostatic stress induced by the diagonal compression test at the center of the wallette. The new interpretation of the diagonal compression test proposed in this article shows that the RILEM guidelines actually underestimate both the hydrostatic and the deviatoric stress states at the center of the wallette. The new formulation complies with the linear elastic theory and allows us to use the diagonal compression test to identify the three elastic coefficients of masonry. In particular, it allows the identification of the Poisson ratio, which instead takes on a conventional value in the RILEM and ASTM guidelines. The difference of one order of magnitude between the conventional and proposed Poisson’s ratio is in agreement with the experimental results on another brittle material, namely concrete. Finally, the new proposal fills the gap between the results provided by the two tests usually performed to identify the shear behavior of masonry: the diagonal compression test and the shear-compression test.
{"title":"A New Proposal for the Interpretation of the Diagonal Compression Test on Masonry Wallettes: The Identification of Young’s Modulus, Poisson’s Ratio, and Modulus of Rigidity","authors":"Elena Ferretti","doi":"10.3390/buildings14010104","DOIUrl":"https://doi.org/10.3390/buildings14010104","url":null,"abstract":"This paper is the continuation of a previous study, which highlighted some inconsistencies in the RILEM guidelines for the interpretation of the diagonal compression test. Although improved compared to the ASTM guidelines, in fact, the RILEM guidelines underestimate the state of hydrostatic stress induced by the diagonal compression test at the center of the wallette. The new interpretation of the diagonal compression test proposed in this article shows that the RILEM guidelines actually underestimate both the hydrostatic and the deviatoric stress states at the center of the wallette. The new formulation complies with the linear elastic theory and allows us to use the diagonal compression test to identify the three elastic coefficients of masonry. In particular, it allows the identification of the Poisson ratio, which instead takes on a conventional value in the RILEM and ASTM guidelines. The difference of one order of magnitude between the conventional and proposed Poisson’s ratio is in agreement with the experimental results on another brittle material, namely concrete. Finally, the new proposal fills the gap between the results provided by the two tests usually performed to identify the shear behavior of masonry: the diagonal compression test and the shear-compression test.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":" 956","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139136412","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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