Buildings

15 pages, 14636 KiB

Open AccessArticle

Reshaping Publicness: Research on Correlation between Public Participation and Spatial Form in Urban Space Based on Space Syntax—A Case Study on Nanjing Xinjiekou

by Mengyao Pan, Yangfan Shen, Qiaochu Jiang, Qi Zhou and Yinghan Li

Buildings 2022, 12(9), 1492; https://doi.org/10.3390/buildings12091492 - 19 Sep 2022

Cited by 13 | Viewed by 2884

Abstract

This paper focuses on urban regeneration practices in central urban areas, aiming to find key points for reshaping the publicness of urban spaces by exploring the morphological features of public spaces and the spatial distribution patterns of public activities. Now that China’s urbanization [...] Read more.

This paper focuses on urban regeneration practices in central urban areas, aiming to find key points for reshaping the publicness of urban spaces by exploring the morphological features of public spaces and the spatial distribution patterns of public activities. Now that China’s urbanization process has stabilized, large-scale regeneration is no longer applicable to the current urban environment, and urban morphology has proved to be significantly useful in understanding and designing the built environment. However, current research lacks quantitative studies on morphology and public activities, and thus is hardly instructive for the cognition and design of spatial morphology in specific locations. Therefore, this paper attempts to subdivide spatial morphology at the level of “micro-renewal” or “micro-renovation” in order to explore the impact of spatial morphology on public participation in cities. The site chosen for this study is Xinjiekou in Nanjing. As a key area of two important arteries in the center of Nanjing, Xinjiekou has been a gathering place for a variety of commercial forms, such as finance, retail department stores, restaurants, and entertainment, and has been the commercial and financial center of Nanjing since the 1940s. In an on-site observation of urban development and pedestrian flow in the Xinjiekou area, the study found that despite its status as the area with the highest degree of spatial accessibility and public participation, its public space has gradually lost its attractiveness to residents, who lack a sense of participation and place identity. Based on the study of urban public spaces, both accessibility and choice play an important role in increasing public participation. Therefore, this study combined observation and quantitative analysis of Space Syntax to obtain the distribution of accessibility, choice, and public activity. Based on the results of the analysis, this research uses GWR as the statistical method to clarify the correlation between different variables. The final conclusion is that when the space type is a path with high choice value and the paths are connected, the enhancement of accessibility and choice plays an important role in promoting public participation. This statistically based empirical study of testable correlations is very helpful for the perception of location-specific spaces with high levels of interpretability and confidence. Thus, it further guides the design and has a high reference value for future spatial planning. Full article

(This article belongs to the Special Issue Computational Analytical Methods for Buildings and Cities: Space Syntax and Shape Grammar)

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29 pages, 6331 KiB

Open AccessArticle

A System Dynamics Approach for Evaluating the Synergy Degree of Social Organizations Participating in Community and Home-Based Elderly Care Services

by Qiuhu Shao, Junwei Ma and Shiyao Zhu

Buildings 2022, 12(9), 1491; https://doi.org/10.3390/buildings12091491 - 19 Sep 2022

Cited by 3 | Viewed by 2019

Abstract

As the number of elderly continues to increase in China, anxiety about related problems has encouraged special care for the elderly. Social organizations participating in community and home-based elderly care services (SO-CHECS) seem to be a promising way to address these problems, but [...] Read more.

As the number of elderly continues to increase in China, anxiety about related problems has encouraged special care for the elderly. Social organizations participating in community and home-based elderly care services (SO-CHECS) seem to be a promising way to address these problems, but it also raises new challenges, such as uncoordinated cooperation among stakeholders, which would lead to low elderly care service quality and hinder the active participation of social organizations. However, synergetic development can be introduced to enhance the participation of social organizations and to improve social welfare. Thus, this study utilizes system dynamics (SD) to investigate how the overall synergy degree of the SO-CHECS system is affected by the dynamic interactions of main elements/subsystems of this system. It also provides a practical tool through which the effectiveness of various management measures in improving the synergy degree of SO-CHECS could be simulated in advance so that the key factors that restrict the development of SO-CHECS can be analyzed and potential effective policies can be designed. In this way, knowledge of the synergic development of the SO-CHECS system will help managers or policy makers to form optimal cooperative relationships among collaborative stakeholders, improve satisfaction for the elderly, and achieve high-efficient resource utilization for the whole city. Full article

(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)

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21 pages, 4900 KiB

Open AccessArticle

Constitutive Material Model for the Compressive Behaviour of Engineered Bamboo

by Janeshka Goonewardena, Mahmud Ashraf, Johannes Reiner, Bidur Kafle and Mahbube Subhani

Buildings 2022, 12(9), 1490; https://doi.org/10.3390/buildings12091490 - 19 Sep 2022

Cited by 5 | Viewed by 1830

Abstract

The mechanical properties of the structural components (i.e., columns and beams produced from engineered bamboo products), such as, bamboo scrimber (also known as parallel bamboo strand lumber, PBSL) and Laminated Bamboo Lumber (LBL), have attracted considerable attention from researchers in recent years. In [...] Read more.

The mechanical properties of the structural components (i.e., columns and beams produced from engineered bamboo products), such as, bamboo scrimber (also known as parallel bamboo strand lumber, PBSL) and Laminated Bamboo Lumber (LBL), have attracted considerable attention from researchers in recent years. In previous studies, researchers reported on the stress-strain behaviour of bamboo scrimber, LBL and glue laminated bamboo under compression and proposed some empirical and semi-empirical models, based on their individual studies. However, a generic constitutive model for engineered bamboo products is still not available. The compressive stress-strain curves of bamboo scrimber and LBL are reported to show a similar behaviour with three distinct stages i.e., a linear elastic stage followed by a nonlinear plastic stage and a plateau. As part of the current study, the previously proposed models for bamboo scrimber were carefully studied and all available material test results on engineered bamboo were used to develop a generic constitutive model, based on the Ramberg-Osgood (RO) formulation considering its suitability to capture its material nonlinearity. Based on the test results, it was observed that 1% proof stress can be used in a compound RO model to predict an accurate material response for bamboo scrimber. The proposed modelling technique has also been applied to predict the compressive behaviour of LBL. This paper proposes the RO coefficients for both bamboo scrimber and LBL that can be used to develop accurate nonlinear models for engineered bamboo products. Full article

(This article belongs to the Special Issue Engineered Wood and Bamboo Composites in Hybrid Buildings)

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28 pages, 12478 KiB

Open AccessArticle

Condition Assessment and Seismic Upgrading Strategy of RC Structures—A Case Study of a Public Institution in Croatia

by Mislav Stepinac, Dominik Skokandić, Karlo Ožić, Margareta Zidar and Matija Vajdić

Buildings 2022, 12(9), 1489; https://doi.org/10.3390/buildings12091489 - 19 Sep 2022

Cited by 10 | Viewed by 2061

Abstract

In 2020, Croatia was struck by two catastrophic earthquakes, resulting in more than 50,000 damaged structures. The majority of these are masonry buildings, but there are a number of reinforced concrete structures that suffered moderate to extensive damage. In this paper, the seismic [...] Read more.

In 2020, Croatia was struck by two catastrophic earthquakes, resulting in more than 50,000 damaged structures. The majority of these are masonry buildings, but there are a number of reinforced concrete structures that suffered moderate to extensive damage. In this paper, the seismic condition assessment and upgrading of existing RC structures are presented with a case study building in Zagreb. The assessment procedure includes initial visual inspection, rapid preliminary evaluation, detailed in situ measurements, and non- and semi-destructive methods. New technologies were applied and followed by numerical modeling and verifications. Strengthening proposals are made that respect owner needs and the needs for the energy retrofitting of the existing RC building. As the integrated approach should be respected in the renovation of existing buildings, this case study can represent an example of good practice in the process of seismic and energy retrofitting. Full article

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26 pages, 8801 KiB

Open AccessArticle

A Comparative Study of the Simulation Accuracy and Efficiency for the Urban Wind Environment Based on CFD Plug-Ins Integrated into Architectural Design Platforms

by Yongyu Hu, Fusuo Xu and Zhi Gao

Buildings 2022, 12(9), 1487; https://doi.org/10.3390/buildings12091487 - 19 Sep 2022

Cited by 7 | Viewed by 2483

Abstract

The deterioration of the urban environment is a problem which has captured the attention of governmental departments and researchers, who are committed to improving the urban environment from the perspective of optimizing urban morphology. Although many researchers have applied computational fluid dynamics (CFD) [...] Read more.

The deterioration of the urban environment is a problem which has captured the attention of governmental departments and researchers, who are committed to improving the urban environment from the perspective of optimizing urban morphology. Although many researchers have applied computational fluid dynamics (CFD) plug-ins to study the problems of urban ventilation and pollutant accumulation, studies on the reliability and simulation accuracy verification of CFD plug-ins are currently scarce. Therefore, we used three CFD plug-ins based on different architectural design platforms to evaluate and compare their operation difficulty, simulation accuracy, and efficiency through the analysis of the simulation results of urban ventilation. This study complements the reliability validation of CFD plug-in simulations and guides urban planners and architects in the selection and application of CFD plug-ins. The results show that the CFD plug-in generally underestimates the wind speed at the pedestrian level and the prediction accuracy is poor in the wake area of obstacles, especially with the GH_Wind plug-in. Under the 0° inflow direction, the simulation results of the Butterfly plug-in were the most consistent with the experimental values. When the inflow direction increased to 22.5° and 45°, the Autodesk CFD showed the best simulation accuracy. Overall, Autodesk CFD achieves a balance between simulation accuracy and speed in urban airflow simulation. Full article

(This article belongs to the Topic Bioclimatic Designs to Enhance Urban/Rural Resilience)

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19 pages, 1242 KiB

Open AccessArticle

A Study of Design Change Management for Infrastructure Development Projects in New Zealand

by Rong Wang, Don Amila Sajeevan Samarasinghe, Lorraine Skelton and James Olabode Bamidele Rotimi

Buildings 2022, 12(9), 1486; https://doi.org/10.3390/buildings12091486 - 19 Sep 2022

Cited by 4 | Viewed by 3875

Abstract

Design changes seem to be an inevitable part of engineering, procurement and construction EPC projects. Such changes create a need for a proactive approach to adjusting project scope, cost and time (the triple constraints) for efficiency and effectiveness in overall delivery. This study [...] Read more.

Design changes seem to be an inevitable part of engineering, procurement and construction EPC projects. Such changes create a need for a proactive approach to adjusting project scope, cost and time (the triple constraints) for efficiency and effectiveness in overall delivery. This study investigates the causes and implications of design changes in order to improve design change management practices. Data for the study were obtained through online interviews with New Zealand industry practitioners. Thematic analysis was used to collate the results into meaningful data. The study found that design changes were predominantly caused by clients’ inadequate strategic planning, insufficient attention to design, EPC contractors’ inadequate design ability, and on-site variations. There were three categories of such design changes: direct impact on the project, the reciprocal and complementary effect on stakeholders, and the far-reaching impact on the community. The study concludes by suggesting improvements, such as strengthening the integration of project teams to enhance design quality, strategic alignment of stakeholders at the planning stage, early contractor involvement (ECI) between the planning and design phases, and improving collaboration between design and construction teams. Further, a combination of high technical skills (e.g., design ability) and soft skills (can-do attitude, interpersonal skills, problem-solving skills, documentation skills, etc.) are needed to generate the desired improvement in design change management. Full article

(This article belongs to the Section Construction Management, and Computers & Digitization)

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18 pages, 36868 KiB

Open AccessArticle

Study on Shear Mechanical Properties and Microscopic Failure Mechanism of Dentate Joints Based on DEM and Laboratory Tests

by Jiaqi Guo, Lipan Cheng, Yongbiao Lai, Yongchao Tian and Lu Li

Buildings 2022, 12(9), 1485; https://doi.org/10.3390/buildings12091485 - 19 Sep 2022

Cited by 4 | Viewed by 1561

Abstract

The stability control of the surrounding rock is greatly influenced by the rock joint’s shear mechanical characteristics and deformation failure mechanism. A numerical model of the dentate joints was created using a particle flow discrete element method (DEM). To study the shear mechanical [...] Read more.

The stability control of the surrounding rock is greatly influenced by the rock joint’s shear mechanical characteristics and deformation failure mechanism. A numerical model of the dentate joints was created using a particle flow discrete element method (DEM). To study the shear mechanical behavior and damage evolution characteristics of the joints, a numerical simulation of the joints shear test under the same normal stress was conducted. Additionally, the joints’ shear failure mechanism and failure mode were investigated from a microscopic perspective in conjunction with laboratory tests. The results show that the shear strength steadily increases as the roughness of the rock joints increases and that it rapidly decreases after reaching its peak shear strength, indicating an obvious brittle failure. Varied rock joints exhibit significantly different micro-crack evolution, with rougher rock joints (r = 0.30, r = 0.37) exhibiting greater micro-crack production and crack extension into the model’s interior. Rock joint specimens with lower roughness (r = 0.17) had less concentration and fewer areas of contact force concentration. The shear failure mode of the rock joints gradually shifts from abrasion failure mode to snip failure mode as the roughness rises, which is largely compatible with the failure characteristics shown in the laboratory testing. The pattern of micro-crack development within the model specimen and the failure characteristics of the laboratory tests are in good agreement with the distribution characteristics of contact force on the rock joints. Full article

(This article belongs to the Special Issue Numerical Analysis on Concrete and Rocks)

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19 pages, 5032 KiB

Open AccessArticle

Seismic Performance Evaluation of a High-Rise Building with Structural Irregularities

by Huijuan Jia, Yongsheng Song, Xi Chen, Shunqing Liu and Binsheng Zhang

Buildings 2022, 12(9), 1484; https://doi.org/10.3390/buildings12091484 - 18 Sep 2022

Cited by 3 | Viewed by 3328

Abstract

In this study, the seismic performances of a 14-storey office building in Nanjing, China, due to its plan and vertical irregularities in the structural system, were evaluated using the response spectrum method, elastic time history analysis and elastic–plastic time history analysis. In combination [...] Read more.

In this study, the seismic performances of a 14-storey office building in Nanjing, China, due to its plan and vertical irregularities in the structural system, were evaluated using the response spectrum method, elastic time history analysis and elastic–plastic time history analysis. In combination of these three methods, the storey drifts and elastic–plastic states of typical structural members under three levels of earthquakes were determined to verify the robustness of the structural design program. The damage states of typical structural members at some sensitive positions were estimated and evaluated under rare earthquakes. Consequently, all structural members were within the scope of elastic performances under the actions of frequent earthquakes. The maximum displacements and storey drifts satisfied the requirements of the design codes within the scope of elastic or elastic–plastic deformations. The induced damages could reach “moderate damage” states, satisfying the requirements for the expected performances by the codes. The consequences indicated that the design scheme and critical parameters for the building structure satisfied the requirements of seismic performances from the codes. Full article

(This article belongs to the Collection Advanced Concrete Structures in Civil Engineering)

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21 pages, 6455 KiB

Open AccessArticle

Research on Experimental and Numerical Methods for Mechanical Properties of Lightweight Hollow Precast Utility Tunnels

by Yutao Feng, Weibin Li and Nan Lu

Buildings 2022, 12(9), 1483; https://doi.org/10.3390/buildings12091483 - 18 Sep 2022

Viewed by 1349

Abstract

In this paper, the mechanical properties of hollow precast utility tunnels are studied by experimental and numerical methods. Through full-scale experiments, the failure modes of ordinary and hollow utility tunnels are studied, and the failure stages of the structures are classified based on [...] Read more.

In this paper, the mechanical properties of hollow precast utility tunnels are studied by experimental and numerical methods. Through full-scale experiments, the failure modes of ordinary and hollow utility tunnels are studied, and the failure stages of the structures are classified based on the bearing capacity and damage to the structures. The nonlinear finite element model is used to simulate the behavior of the structure, and the optimal design of the structure under load type and the hollow ratio are discussed based on the finite element method. The theoretical calculation method of the bearing capacity for hollow structures in each stage is proposed, and its application scope is discussed. The finite element analysis can effectively predict the mechanical properties of the structure, and the failure of the utility tunnel structure is dependent on the shear bearing capacity. Although hollow design advances the structural damage under point load, the hollow structure has significant advantages under uniform loads or reasonable hollow ratios. It is reasonable to calculate the cracking load considering moment distribution at section centroid and the failure load considering the combined action of flexural and shear stress, but the hollow ratio should be less than 16%. Under reasonable hollow ratio or load conditions, the hollow design has little effect on the bearing capacity of the structure and can reduce the weight, which has practical value for architecture and construction. Full article

(This article belongs to the Special Issue Prefabricated Spatial Network Structure)

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19 pages, 2557 KiB

Open AccessArticle

Review of the Cost-Optimal Methodology Implementation in Member States in Compliance with the Energy Performance of Buildings Directive

by Paolo Zangheri, Delia D’Agostino, Roberto Armani and Paolo Bertoldi

Buildings 2022, 12(9), 1482; https://doi.org/10.3390/buildings12091482 - 17 Sep 2022

Cited by 7 | Viewed by 2467

Abstract

The building sector has a central role in achieving the European goals of a zero-emission and fully decarbonized stock by 2050. Among the provisions of the Energy Performance of Buildings Directive (EPBD) recast, the implementation of the cost-optimal methodology marked a novel approach [...] Read more.

The building sector has a central role in achieving the European goals of a zero-emission and fully decarbonized stock by 2050. Among the provisions of the Energy Performance of Buildings Directive (EPBD) recast, the implementation of the cost-optimal methodology marked a novel approach in the establishment of minimum energy performance requirements for new and existing buildings. Member States must develop cost-optimal calculations every 5 years to verify and accordingly update the national requirements in force. This paper analyses the latest national cost-optimal reports, providing an updated assessment of the implementation of the cost-optimal methodology throughout Europe. It quantifies the progress in reaching cost-optimal levels in comparison with the previous assessment. It focuses on the conformity and plausibility of calculations in compliance with the policy framework. Furthermore, it evaluates the gap with national requirements, showing that the gap is higher than 15% only in a few Member States. The results provide a comprehensive review of the European progress towards cost-optimality in both the residential sector (average cost-optimal level 80 kWh/m²y for new, 130 kWh/m²y for existing buildings) and the non-residential sector (140 kWh/m²y for new, 180 kWh/m²y for existing buildings). An overall positive development can be inferred from the analysis of the Member States’ progress in the methodology’s implementation. The review also gives inputs for the cost-optimal methodology update foreseen for 2026 (e.g., cost-optimality for districts and historical buildings). The outcomes assume a crucial relevance for the ambitious energy efficiency targets established by Europe. Full article

(This article belongs to the Special Issue Advanced Studies in Nearly Zero-Energy Buildings and Optimal Design)

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22 pages, 7359 KiB

Open AccessArticle

Machine Learning-Aided Prediction of Post-Fire Shear Resistance Reduction of Q690 HSS Plate Girders

by Guiwen Liu, Jie Liu, Neng Wang, Xuanyi Xue and Youjia Tan

Buildings 2022, 12(9), 1481; https://doi.org/10.3390/buildings12091481 - 17 Sep 2022

Cited by 6 | Viewed by 1508

Abstract

Fire has significant effects on the residual resistance of steel structures. It is necessary to accurately clarify its effects on Q690 HSS plate girders, which have been widely used. In this paper, the ultimate resistance and effective service resistance of Q690 HSS plate [...] Read more.

Fire has significant effects on the residual resistance of steel structures. It is necessary to accurately clarify its effects on Q690 HSS plate girders, which have been widely used. In this paper, the ultimate resistance and effective service resistance of Q690 HSS plate girders after a fire are obtained using material tests and finite element (FE) analysis including parametric studies, where the data of 210 models were collected. The effects of four key parameters (h_w/t_w ratio, a/h_w ratio, exposure temperature and cooling method) on post-fire shear resistance reduction of Q690 HSS plate girders are roughly investigated by individual conditional expectation (ICE), showing exposure temperature is the most important factor. The popular algorithms of machine learning (ML), namely artificial neural network (ANN) and support vector regression (SVR) algorithms, are utilized in model training to predict the reduction factors of both ultimate resistance and effective service resistance. Finally, the results indicate that the prediction using ML shows much better performance than that with traditional ordinary least squares (OLS) regression, and SVR with genetic algorithm (GA) provides the highest prediction accuracy. The results of this paper show the superiority of machine learning for solving prediction problems of steel structures, compared with conventional methods such as linear regression. Full article

(This article belongs to the Special Issue Recent Advances in Constructional Steel Research)

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21 pages, 8622 KiB

Open AccessArticle

Investigations on the Dynamic Response of Adjacent Buildings Connected by Viscous Dampers

by Peng Chen and Xiaobin Wu

Buildings 2022, 12(9), 1480; https://doi.org/10.3390/buildings12091480 - 17 Sep 2022

Cited by 7 | Viewed by 2079

Abstract

This paper investigates the seismic performance of two adjacent buildings connected by viscous dampers. Three types of damper placement are discussed, including installing dampers within a single building, connecting two buildings at the same floor level, and connecting two buildings at the inter-story [...] Read more.

This paper investigates the seismic performance of two adjacent buildings connected by viscous dampers. Three types of damper placement are discussed, including installing dampers within a single building, connecting two buildings at the same floor level, and connecting two buildings at the inter-story level. Analytical models are established to consider various dynamic properties of the adjacent buildings, and the theoretical solutions are obtained, including the transmissibility curves, additional modal damping, and input energy under the seismic design spectrum. Time history analyses of an engineering project are performed with different damper placements. Different numerical models are compared for frequently and rarely occurred earthquakes. The seismic mitigation effect is discussed with regard to the story drift reduction rate and dynamic energy. Theoretical and numerical results demonstrate that the connecting dampers provide added modal damping while causing the coupled response. As a result, it is less efficient than traditional ways of placement within a building. Furthermore, the connecting dampers significantly increase the reaction of the floors without installed dampers. When designing dampers to connect the adjacent buildings, careful engineering calculations should be made. Full article

(This article belongs to the Special Issue Advances in Design and Disaster Mitigation of Engineering Structures)

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21 pages, 1802 KiB

Open AccessArticle

Design, Development and Implementation of a Novel Parallel Automated Step Response Testing Tool for Building Automation Systems

by Athila Santos, Na Liu and Muhyiddine Jradi

Buildings 2022, 12(9), 1479; https://doi.org/10.3390/buildings12091479 - 17 Sep 2022

Cited by 3 | Viewed by 1530

Abstract

The digital transformation has paved the path for new services and efficient management across the value chain of the whole energy sector. For applications behind the meter, buildings stand out as a major contributor to energy consumption and corresponding emissions. Therefore, Building Automation [...] Read more.

The digital transformation has paved the path for new services and efficient management across the value chain of the whole energy sector. For applications behind the meter, buildings stand out as a major contributor to energy consumption and corresponding emissions. Therefore, Building Automation Control Systems (BACS) have been proposed in order to mitigate building performance issues. Finding optimal and automated methods to handle different control points of BACS is very important. In the initial design and commissioning phases, HVAC systems need to be tested exhaustively to guarantee proper function and expected operation compliance. However, the availability of automated step response test tools applied in the building sector is still scarce, forcing engineers around the globe to manually test different scenarios over the same buildings multiple times. This is a tedious and error-prone approach that lacks precision and good resource allocation. Therefore, we propose AUSTRET: a parallel automated multiple processing software for step response testing in buildings. The tool aims to automate the laborious step response tests of BACS cost-effectively. The input parameters can be provided for several control zones and on different control systems. The multi-processing capability allows the step response execution to run in parallel saving time and resources from the operators. The implementation of AUSTRET is first tested in a living lab environment in a university office building and then demonstrated on full-scale in a commercial building setting. The results show how the parallel processing capability of AUSTRET enhances the productivity and efficiency of step response tests in a building and how the different configuration parameters can affect the overall performance of the tests. The preliminary results indicate how automated tools, such as AUSTRET, can improve the automation and effectiveness of step response tests in the design phase or during retro-commissioning building processes. Full article

(This article belongs to the Section Building Energy, Physics, Environment, and Systems)

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16 pages, 1834 KiB

Open AccessTechnical Note

Development of a New Uplift Pile with Prestressed Semi-Bonded Composite Anchor

by Zongyuan Mao, Hao Guo, Yongkang Wu, Enzhi Wang and Xu Li

Buildings 2022, 12(9), 1478; https://doi.org/10.3390/buildings12091478 - 17 Sep 2022

Cited by 3 | Viewed by 3788

Abstract

This paper introduces a new type of prestressed uplift pile that adopts the semi-bonded composite anchor as the main reinforcement. An in-situ experimental study was carried out to investigate the new pile’s deformation, stress, bearing capacity, and cracking characteristics, which were then compared [...] Read more.

This paper introduces a new type of prestressed uplift pile that adopts the semi-bonded composite anchor as the main reinforcement. An in-situ experimental study was carried out to investigate the new pile’s deformation, stress, bearing capacity, and cracking characteristics, which were then compared with the conventional piles. Results show that although the reinforcement ratio of the new pile is only 0.75%, much less than that of the conventional pile (i.e., 3.84%), it achieves similar or even better mechanical properties under uplift loads. The cost of the pile’s anchorage system is reduced by 43.8%, and the total cost of a single pile is reduced by 33.6%. Compared with the conventional pile, the new pile makes better use of the lateral friction resistance of the lower pile body, and the uplift bearing capacity and the uplift resistance of the pile are improved correspondingly. In addition, the cracking resistance of the new pile is significantly improved, with the cracking load increased by 88.2% and the cracking area reduced by 48.3%. In addition, the multi-layer structure of the composite main bar provides better protection for the load-bearing steel strands against corrosion. As such, the new type of pile is expected to gain much better durability than the conventional ones. Full article

(This article belongs to the Special Issue Advances in Soils and Foundations)

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26 pages, 810 KiB

Open AccessArticle

Measuring Work Autonomy and Its Role in Enhancing Labour Productivity: The Case of the Vietnamese Construction Industry

by Nguyen Van Tam, Tsunemi Watanabe and Nguyen Luong Hai

Buildings 2022, 12(9), 1477; https://doi.org/10.3390/buildings12091477 - 17 Sep 2022

Cited by 3 | Viewed by 1773

Abstract

Work autonomy (WA) is an important factor in improving work performance, yet such freedom and its role in construction workforce management have rarely been discussed. To address this gap, this study quantitatively measured the WA of onsite construction workers in Vietnam, developed a [...] Read more.

Work autonomy (WA) is an important factor in improving work performance, yet such freedom and its role in construction workforce management have rarely been discussed. To address this gap, this study quantitatively measured the WA of onsite construction workers in Vietnam, developed a new model by which to discover the function of WA in increasing construction labour productivity (CLP) and determined the ways through which WA can be cultivated and maintained. The WA of 215 workers was measured using the relative autonomy index (RAI) and an aggregated motivation index (AMI) that was developed in this research. Structural equation modelling (SEM) was conducted to examine the effects of WA on CLP. The SEM results indicated that WA positively and significantly contributed to CLP. Promoting WA required paying attention to the competence and relatedness satisfaction of the workers. Furthermore, latent and potentially extensive labour management-related problems were identified, namely, unsuccessful career development and the underutilisation of experienced workers. Three meaningful policy recommendations were put forward to solve the aforementioned problems and improve CLP: the effective organisation of crew members, the improvement of training and the improvement of site amenities. This study expands theoretical knowledge by (1) developing and justifying the AMI as an auxiliary to conventional indices, (2) proposing five conditions necessary for optimal scoring in WA measurement and (3) developing a motivation matrix that identifies and distinguishes the attributes of different groups. In practical terms, the findings support the introduction of reasonable policies that advance the career development of workers, promote WA and improve CLP. These achievements, in turn, significantly advance effective and sustainable construction workforce management. Full article

(This article belongs to the Section Construction Management, and Computers & Digitization)

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13 pages, 650 KiB

Open AccessArticle

Quantitative and Qualitative Analysis of Applying Building Information Modeling (BIM) for Infrastructure Design Process

by Min-Ho Shin, Ji-Hyun Jung and Hwan-Yong Kim

Buildings 2022, 12(9), 1476; https://doi.org/10.3390/buildings12091476 - 17 Sep 2022

Cited by 9 | Viewed by 3564

Abstract

Building information modeling (BIM) has opened up many possibilities for the construction industry. However, most studies focus mainly on its overall uses and management areas. By investigating real projects that could utilize BIM in the design phases for railway construction, the authors examine [...] Read more.

Building information modeling (BIM) has opened up many possibilities for the construction industry. However, most studies focus mainly on its overall uses and management areas. By investigating real projects that could utilize BIM in the design phases for railway construction, the authors examine the possible advantages and disadvantages in BIM implementation. To do so, the authors have selected three projects that utilized BIM implementation during the design process and three other projects with a non-BIM, traditionally designed working environment. Similar-scale projects were carefully chosen, and their differences in costs, man-hours, and labor forces were analyzed quantitatively. In addition, an in-depth interview was conducted with four BIM-designing firms to provide a more comprehensive perspective on the advantages and issues in BIM implementation. The average results showed that BIM-implemented projects spent USD 65,800 less than their counterparts and could increase productivity by about 2.9%. More importantly, the primary difference between BIM and non-BIM projects are in their man-hours. BIM-adopting projects spent 103.5 days less than non-BIM projects on average, and required three fewer professional labor forces during the entire design process. Full article

(This article belongs to the Section Construction Management, and Computers & Digitization)

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16 pages, 3159 KiB

Open AccessArticle

Analysis of Particulate and Microbiological Filtration Performance of Air Handling Unit Filters in a Low-Energy Office Building over 12 Months

by Gaëtan Pavard, Aurélie Joubert, Yves Andrès and Pierre Le Cann

Buildings 2022, 12(9), 1475; https://doi.org/10.3390/buildings12091475 - 17 Sep 2022

Cited by 1 | Viewed by 1875

Abstract

Indoor air quality is an important consideration for the health and well-being of building occupants, and the SARS CoV-2 pandemic highlighted the importance of maintaining proper ventilation in buildings. Air handling units (AHUs) are used to provide fresh air and maintain occupant comfort. [...] Read more.

Indoor air quality is an important consideration for the health and well-being of building occupants, and the SARS CoV-2 pandemic highlighted the importance of maintaining proper ventilation in buildings. Air handling units (AHUs) are used to provide fresh air and maintain occupant comfort. The objective of this work was to study the evolution of filtration efficiency in an AHU fitted with bag filters, installed to treat office air in a low-energy building, over a 12-month period. The particulate filtration efficiency (PFE) and the microbial filtration efficiency (MFE) were quantified by measuring particle size distribution and bacterial and fungal concentration in the air circulating in the AHU. The resulting microbial concentration measurements in the fresh air (between 10²–10³ CFU/m³ for fungi and around 10³ CFU/m³ for bacteria) were higher than those in the extracted air from the offices (between 10¹ and 10² CFU/m³ for fungi and around 10² CFU/m³ for bacteria). The PFE and MFE measured were almost constant throughout the 12 months, with an increase of the filter pressure drop from 70 to 90 Pa. The PFE and MFE were quite comparable for a particle diameter. Therefore, the measurement of PFE is a reliable indicator of the MFE. Full article

(This article belongs to the Special Issue Advances in the Indoor Environments and Respiratory Health)

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16 pages, 5794 KiB

Open AccessArticle

Optimization of the Seismic Performance of a Steel-Concrete Wind Turbine Tower with the Tuned Mass Damper

by Yanchao Yue, Changxin Li, Kai Jia, Yuhang Zhang and Jingjing Tian

Buildings 2022, 12(9), 1474; https://doi.org/10.3390/buildings12091474 - 17 Sep 2022

Cited by 6 | Viewed by 1564

Abstract

To optimize the seismic performance of a new type of steel-concrete tower, a 120 m steel-concrete composite tower model with a tuned mass damper (TMD) was constructed in ABAQUS for simulation analysis. Firstly, a time history analysis was conducted to study the towers [...] Read more.

To optimize the seismic performance of a new type of steel-concrete tower, a 120 m steel-concrete composite tower model with a tuned mass damper (TMD) was constructed in ABAQUS for simulation analysis. Firstly, a time history analysis was conducted to study the towers with and without a TMD to determine the difference in their accelerations, velocities, and displacements. Then, a frequency spectrum analysis was performed to determine the tower vibration reduction effect of TMDs with different mass ratios. Five different cases were considered to explore the impact of different layouts on the dynamic performance of the tower. The results showed that the TMD had a significant vibration reduction effect on the tower accelerations, velocities, and displacements. The acceleration was reduced the most, while the vibration reduction effect in the middle of the tower was more significant than that at the top of the tower. For the steel-concrete tower studied in this paper, the optimal mass ratio of TMD was found to be 0.01. Placing one TMD at the top and another in the middle of the tower was found to be the optimal TMD arrangement for tower vibration reduction. Full article

(This article belongs to the Special Issue Improvement Technology on Building Seismic Toughness)

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22 pages, 9838 KiB

Open AccessFeature PaperArticle

Multi-Objective Optimisation of Urban Form: A Framework for Selecting the Optimal Solution

by Milad Showkatbakhsh and Mohammed Makki

Buildings 2022, 12(9), 1473; https://doi.org/10.3390/buildings12091473 - 17 Sep 2022

Cited by 8 | Viewed by 2697

Abstract

The complexity associated with the design of urban tissues is driven by the multitude of design goals that influence urban development and growth. This complexity is amplified by the design goals being inherently conflicting, necessitating preference-based decisions within the design process—an approach that [...] Read more.

The complexity associated with the design of urban tissues is driven by the multitude of design goals that influence urban development and growth. This complexity is amplified by the design goals being inherently conflicting, necessitating preference-based decisions within the design process—an approach that results in predetermined design solutions driven by personal biases. The utility of population-based optimisation algorithms addresses this by allowing for the examination of multiple conflicting objectives within the same design problem, negating the need for trade-off decisions between the design goals. The application of these algorithms is associated with three primary steps. The first is the formulation of the design problem, the second is the application of the algorithm, and the third is selecting the most optimal solution from the algorithm’s output. This paper examines the third step in this process, in which various methods are employed to facilitate data-driven selection mechanisms that are both objective as well as subjective in their formulation. The selection mechanisms are demonstrated on a speculative urban tissue that examines the potential of inhabiting interstitial spaces, through various morphological interventions, within the urban fabric. The results present a scalable and adaptable framework that assists designers employing multi-objective evolutionary algorithms (MOEAs) to select the optimal solution from their generated populations, a challenge commonly associated with the application of MOEAs in design. Full article

(This article belongs to the Collection Performance-Based Urban Design: Integrated Urban Analytics, Simulation and Climate-Responsive Design)

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20 pages, 2848 KiB

Open AccessFeature PaperArticle

BIM-Based Resource Tradeoff in Project Scheduling Using Fire Hawk Optimizer (FHO)

by Milad Baghalzadeh Shishehgarkhaneh, Mahdi Azizi, Mahla Basiri and Robert C. Moehler

Buildings 2022, 12(9), 1472; https://doi.org/10.3390/buildings12091472 - 16 Sep 2022

Cited by 21 | Viewed by 2436

Abstract

Project managers should balance a variety of resource elements in building projects while taking into account many major concerns, including time, cost, quality, risk, and the environment. This study presents a framework for resource trade-offs in project scheduling based on the Building Information [...] Read more.

Project managers should balance a variety of resource elements in building projects while taking into account many major concerns, including time, cost, quality, risk, and the environment. This study presents a framework for resource trade-offs in project scheduling based on the Building Information Modeling (BIM) methodology and metaheuristic algorithms. First, a new metaheuristic algorithm called Fire Hawk Optimizer (FHO) is used. Using project management software and the BIM process, a 3D model of the construction is created. In order to maximize quality while minimizing time, cost, risk, and CO₂ in the project under consideration, an optimization problem is created, and the FHO’s capability for solving it is assessed. The results show that the FHO algorithm is capable of producing competitive and exceptional outcomes when it comes to the trade-off of various resource options in projects. Full article

(This article belongs to the Special Issue Information Technologies in Construction: Present Status and Future Trends)

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28 pages, 5856 KiB

Open AccessArticle

Case Study of the Application of an Innovative Guide for the Seismic Vulnerability Evaluation of Schools Located in Sangolquí, Interandean Valley in Ecuador

by Kevin Sebastián Ballesteros-Salazar, Diego German Caizaguano-Montero, Ana Gabriela Haro-Báez and Theofilos Toulkeridis

Buildings 2022, 12(9), 1471; https://doi.org/10.3390/buildings12091471 - 16 Sep 2022

Cited by 2 | Viewed by 2284

Abstract

The current study is based on the analysis and adaptation of a Federal Emergency Management Agency guide, FEMA P-1000, from the USA to improve school safety against natural hazards by applying the guide to the infrastructure of Ecuadorian schools, focusing primarily on seismic [...] Read more.

The current study is based on the analysis and adaptation of a Federal Emergency Management Agency guide, FEMA P-1000, from the USA to improve school safety against natural hazards by applying the guide to the infrastructure of Ecuadorian schools, focusing primarily on seismic risk. By considering the technical foundations of structuring and managing disasters in buildings for school use, society will be provided with a practical procedure to recognize those aspects that need immediate attention as part of proper risk management. Here, a variety of parameters are involved in the proposed methodology of the given guide from FEMA combined with the national construction standards and regulations. The characteristics of nearby geological faults and structural and nonstructural vulnerability levels, amongst others, were also considered to allow for a detailed evaluation and a subsequent seismic risk categorization. Finally, the global risk is determined for the studied institutions of Sangolquí in the Valley of Los Chillos, within the Interandean Depression in central Ecuador. Full article

(This article belongs to the Section Building Structures)

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17 pages, 6181 KiB

Open AccessArticle

Laws and Numerical Analysis of Surface Deformation Caused by Excavation of Large Diameter Slurry Shield in Upper-Soft and Lower-Hard Composite Stratum

by Yuan Mei, Dongbo Zhou, Wenyan Shi, Yuhang Zhang and Yu Zhang

Buildings 2022, 12(9), 1470; https://doi.org/10.3390/buildings12091470 - 16 Sep 2022

Cited by 6 | Viewed by 1533

Abstract

Due to the large cross-section design of large-diameter shield tunnels, most of the rocks and soils it crosses are composite strata with upper soft and lower hard. In order to reduce the construction cost of shield working shafts, large-diameter shield launching is usually [...] Read more.

Due to the large cross-section design of large-diameter shield tunnels, most of the rocks and soils it crosses are composite strata with upper soft and lower hard. In order to reduce the construction cost of shield working shafts, large-diameter shield launching is usually buried at a shallow depth. Based on the typical large-diameter slurry shield tunnel, the following research results were obtained according to field monitoring and PLAXIS 3D finite element simulation. (1) The electronic level is used to monitor the surface settlement, and the field monitoring data were obtained; the surface settlement duration curve at the axis of the shield tunnel during the construction period can be divided into four stages: pre-deformation, shield passing, shield tail exit and shield moving away, of which the surface settlement accounts for the largest proportion during the shield passing. (2) In order to ensure the accuracy of the numerical simulation results, the linear shrinkage of the shield needs to be considered in the modeling. (3) The maximum surface settlement value at the center of the tunnel increases with the increase of the support pressure; when the support pressure exceeds 300 kPa, the surface uplift and the settlement caused by the formation loss will offset, and the surface settlement will decrease instead. The maximum surface settlement value is inversely proportional to the grouting pressure, but with the increase of the grouting pressure, the maximum uplift of the surface continues to increase. (4) With the numerical simulation of excavation step construction, the surface uplift increases with the increase of grouting pressure and shield radius, and decreases with the increase of shield buried depth. Full article

(This article belongs to the Collection Innovation of Materials and Technologies in Civil Construction)

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19 pages, 2363 KiB

Open AccessArticle

Embodied and Operational Energy of a Case Study Villa in UAE with Sensitivity Analysis

by Abdul Rauf, Daniel Efurosibina Attoye and Robert Crawford

Buildings 2022, 12(9), 1469; https://doi.org/10.3390/buildings12091469 - 16 Sep 2022

Cited by 8 | Viewed by 2689

Abstract

Extensive focus on operational energy research has positively impacted both academia and policymakers, facilitating new strategies that reduce the energy consumed by building occupants. Much less emphasis has, however, been given to embodied energy. Consequently, although studies now show that embodied energy can [...] Read more.

Extensive focus on operational energy research has positively impacted both academia and policymakers, facilitating new strategies that reduce the energy consumed by building occupants. Much less emphasis has, however, been given to embodied energy. Consequently, although studies now show that embodied energy can be responsible for up to 50% of a building’s life cycle energy, little is known about the embodied energy associated with the construction of buildings, materials, and components in the study context. The aim of this study is to investigate the current scenario in the United Arab Emirates (UAE) by calculating the embodied energy of a residential villa, and estimating the initial, recurrent, and demolition and disposal embodied energies over a 50-year building life span. A detailed assessment of the embodied energy associated with the construction of the case study villa was carried out using an input–output hybrid approach, followed by a sensitivity analysis focused on variations related to the energy associated and consumed, as well as the adoption of renewable energy sources. The findings show that the initial embodied energy was 57% of the life cycle embodied energy and 19% of the life cycle energy of the villa while the recurrent embodied energy was 43% of the life cycle embodied energy and 14% of the life cycle energy of the villa. The life cycle embodied energy of the villa, over a 50-year life span was 36% of the life cycle energy. This paper also highlights the impact of adding a solar PV system and lists multiple areas for future studies related to embodied energy and its benefit to stakeholders in the building industry. Full article

(This article belongs to the Special Issue ZEMCH—Zero Energy Mass Custom Home International Research 2021)

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18 pages, 3835 KiB

Open AccessArticle

Constrained Mode–Damping Solvent Extraction Combined Method for the Soil Incorporation into a Real-Time Hybrid Test of the Soil–Structure System

by Lanfang Luo and Nan Jiang

Buildings 2022, 12(9), 1468; https://doi.org/10.3390/buildings12091468 - 16 Sep 2022

Viewed by 962

Abstract

The real-time hybrid test is an effective testing method for soil–structure interaction research. Due to the data interaction time requirement and formula derivation method, the traditional real-time hybrid test of soil–structure interaction mostly employs a simple numerical substructure model. This study investigated the [...] Read more.

The real-time hybrid test is an effective testing method for soil–structure interaction research. Due to the data interaction time requirement and formula derivation method, the traditional real-time hybrid test of soil–structure interaction mostly employs a simple numerical substructure model. This study investigated the model construction and numerical simulation of a finite element soil substructure with high simulation accuracy and calculation efficiency. The soil was subdivided into near-field and far-field zones. A constrained mode–damping solvent extraction combined method was applied to the latter zone, reducing the soil’s computational scale and simulating the far-field energy dissipation effect. Then, the basic formula of the near-field zone–structure system was derived using the branch mode method, and the motion equation of the soil–structure system applied to real-time hybrid test was obtained. The soil’s numerical model was realized by the joint application of ANSYS and MATLAB software packages and verified through the real-time hybrid test of the soil–structure system. The results show that the proposed constrained mode–damping solvent extraction combined method had high calculation efficiency and good accuracy. It satisfied the requirements of the soil numerical substructure in real-time hybrid tests. Full article

(This article belongs to the Special Issue High Performance Steel Structures)

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19 pages, 7993 KiB

Open AccessArticle

Study on Mix Proportion Design Based on Strength and Sulfate Resistance of 100% Recycled Aggregate Concrete

by Haizhou Li, Jianping Liu, Fujiao Chu and Lu Zhang

Buildings 2022, 12(9), 1467; https://doi.org/10.3390/buildings12091467 - 16 Sep 2022

Cited by 4 | Viewed by 1627

Abstract

This paper presents the mechanical properties of 100% recycled aggregate concrete (RAC), and the results and analysis of the dry–wet cycle accelerated sulfate attack test. The results show that recycled concrete aggregate (RCA) can replace the coarse and fine aggregate. The recycled clay [...] Read more.

This paper presents the mechanical properties of 100% recycled aggregate concrete (RAC), and the results and analysis of the dry–wet cycle accelerated sulfate attack test. The results show that recycled concrete aggregate (RCA) can replace the coarse and fine aggregate. The recycled clay brick aggregate (RCBA) is not suitable for use as a coarse aggregate because the water absorption exceeds the standard. RCA replaces the coarse aggregate; and RCBA returns the fine aggregate to prepare 100% recycled concrete aggregate (RAC). The water–cement ratio is the most significant factor affecting the compressive strength of 100% RAC. The results of the mechanical properties analysis show that the compressive strength of RAC is less than that of NAC, and the difference in compressive strength between 100% RAC and NAC decreases with age. The splitting tensile strength of 100% RAC was slightly higher than that of NAC except for 7 d. The results of the dry–wet cycle accelerated sulfate attack test showed that the performance of 100% RAC was lower than that of NAC under the dry–wet process and sulfate attack coupling. Still, the loss rate was less than 5%, which met the standard resistance to the dry–wet cycle accelerating the sulfate attack. Full article

(This article belongs to the Section Building Materials, and Repair & Renovation)

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18 pages, 4387 KiB

Open AccessArticle

Production of the Traditional Organic Mortars of Padmanabhapuram Palace—A Characterization Study on the Simulated Mortars for Their Compatibility

by Mani Shivakumar, Aruna Singh, Thirumalini Selvaraj and Shanmugapriya Thangaraj

Buildings 2022, 12(9), 1466; https://doi.org/10.3390/buildings12091466 - 16 Sep 2022

Cited by 1 | Viewed by 1795

Abstract

The scientific investigation performed on the different mortar typologies of the Padmanabhapuram Palace mortars in a previous study led to the formulation of a similar traditional mortar. The outcome of the study was an increase in the carbonation action and mechanical strength of [...] Read more.

The scientific investigation performed on the different mortar typologies of the Padmanabhapuram Palace mortars in a previous study led to the formulation of a similar traditional mortar. The outcome of the study was an increase in the carbonation action and mechanical strength of the mortar compared to conventional lime mortar, primarily due to the fermented organics such as aloe vera, cactus, kadukkai, hibiscus, jaggery, and neelamari. The transformation of portlandite crystals to calcite, along with the early developed C-S-H and C-A-S-H hydrated products reported by the XRD analysis. The bio-organic spectral peaks for compounds such as carbohydrates, polysaccharides, and fatty acids were observed in the FT-IR investigation, which corroborates the XRD mineralogical results. The calcite decomposition is detected in the TGA analysis in the temperature range of 700–750 °C, with a maximum weight loss of approximately 35–37% for the aloe vera lime mortar. The addition of fermented organic extracts to the extent of 5% was found to increase the internal and external carbon absorption of the aloe vera and cactus mortars compared to conventional lime mortars. The mechanical strength of the organic lime mortar reported as 2.5 MPa, and 1.5 MPa for the reference mortar. The carbonation and hydraulic reactions due to the presence of polysaccharides, fatty acids, carbohydrates, and proteins in the formulation enhanced the compressive strength of the compatible mortar. The prepared compatible mortar will support the revival of the 400-year-old practice of the application of Palace mortars. Full article

(This article belongs to the Section Building Materials, and Repair & Renovation)

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19 pages, 6693 KiB

Open AccessArticle

Study on Seismic Performance of TID-LRB Hybrid Control System under Multi-Level Earthquakes

by Xiao Huang, Zhixiang Hu, Yunlin Liu and Liqing Nie

Buildings 2022, 12(9), 1465; https://doi.org/10.3390/buildings12091465 - 16 Sep 2022

Cited by 3 | Viewed by 1204

Abstract

The seismic response characteristics of a lead-rubber-bearing(LRB) base-isolated structure under rare and very rare earthquakes were investigated. The acceleration, ductility coefficient, and shear strain of the LRB increase significantly under very rare earthquakes in comparison to rare earthquakes; in particular, the shear strain [...] Read more.

The seismic response characteristics of a lead-rubber-bearing(LRB) base-isolated structure under rare and very rare earthquakes were investigated. The acceleration, ductility coefficient, and shear strain of the LRB increase significantly under very rare earthquakes in comparison to rare earthquakes; in particular, the shear strain of the LRB may exceed the ultimate shear strain and cause damage to the base-isolated structure. The criterion selected for the optimum tuned inerter damper (TID) of the TID–LRB hybrid control system is the minimization of the mean value of the maximum shear strain of the LRB. For each inertance mass ratio of the TID, there exists an optimum tuning frequency ratio and damping ratio of the TID to minimize the shear strain of the LRB, and the effectiveness is increased with a higher inertance mass ratio. By equipping the TID with appropriate parameters, the safety of the LRB during rare and very rare earthquakes can be ensured. Finally, the pounding response of the base-isolated structure collision with the moat wall under very rare earthquakes was analyzed. It was observed that under very rare earthquakes, the ductility coefficients of the superstructure by equipping with the suitable TID were improved, and the shear strain of the LRB was reduced. In addition, equipping the TID can reduce the required width of the isolation joint to avoid collision between the isolation layer and the moat wall, and with an increase in the inertance mass ratio, the required width of the isolation joint is smaller. Full article

(This article belongs to the Special Issue Advanced Studies of Risk Resistant Building Structures)

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18 pages, 6264 KiB

Open AccessArticle

Study on Dynamic Response Characteristics of Stepped Reinforced Retaining Wall

by Yalin Zhu, Renyi Chen, Yixian Wang and Juxiang Chen

Buildings 2022, 12(9), 1464; https://doi.org/10.3390/buildings12091464 - 16 Sep 2022

Viewed by 1306

Abstract

In order to further explore the influence of reinforcement materials laying position on the dynamic characteristics of reinforced retaining walls, based on FLAC3D finite difference methods for solving nonlinear problems, established with the same size of the retaining wall in practical engineering, the [...] Read more.

In order to further explore the influence of reinforcement materials laying position on the dynamic characteristics of reinforced retaining walls, based on FLAC3D finite difference methods for solving nonlinear problems, established with the same size of the retaining wall in practical engineering, the reinforcement material’s relative position in the retaining wall for the normalized processing, under seismic load, and the panel under the conditions of different reinforcement arrangement were analyzed, and the horizontal displacement of slope, the vertical and horizontal earth pressures behind the wall, and the distribution of potential sliding surface were calculated. The relationship between the maximum horizontal displacement of the panel and the laying position of the reinforcement was fitted by MATLAB. The results show that the horizontal displacement of the panel is about 40% smaller when the upper layer of the reinforcement is arranged than that in the lower layer for step 1, and the horizontal displacement of the reinforcement in step 2 is about 30% lower than that in other conditions when the reinforcement is arranged at the top of the slope. The reinforcement arranged in the lower layer of step 1 and the upper layer of step 2 can minimize the wall top displacement. In step 1, the vertical earth pressure and horizontal earth pressure are 19% and 5% smaller than those in other conditions when the reinforcement is arranged near the middle and lower layer of the step. In step 2, the difference between vertical and horizontal earth pressure is not obvious, and the difference between the two conditions is controlled within 5%. At the same time, soil liquefaction and uplift occur under the action of earthquake. The position of sliding crack surface has no obvious regularity with the position of reinforcement, but the position of reinforcement at the step classification is obviously better than other conditions. The fitting formula can describe the relationship between the panel displacement and the position of the reinforcement well. The conclusions can provide a point of reference for practical engineering. Full article

(This article belongs to the Section Building Structures)

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13 pages, 2162 KiB

Open AccessArticle

A Field Study of Outdoor Human Thermal Perception in Three Seasons in Shanghai, China

by Dongxue Wei, Zefeng Lian and Binyi Liu

Buildings 2022, 12(9), 1453; https://doi.org/10.3390/buildings12091453 - 16 Sep 2022

Cited by 3 | Viewed by 1443

Abstract

The locality of landscape design needs to obtain human thermal perception in different cities or regions. Previous studies in Shanghai have focused on a single season and ignored the seasonal characteristics of hot summers and cold winters. The objective of this research was [...] Read more.

The locality of landscape design needs to obtain human thermal perception in different cities or regions. Previous studies in Shanghai have focused on a single season and ignored the seasonal characteristics of hot summers and cold winters. The objective of this research was to examine the outdoor human thermal perception in three seasons—summer, autumn, and winter. For this purpose, a field survey was conducted in two urban squares in Shanghai, and during three seasons, an outdoor human thermal perception questionnaire survey was completed combined with micrometeorological measurements. In the questionnaire, the thermal sensation and thermal comfort of interviewees were evaluated through the 9-point scale and the 4-point break scale, respectively. Regression lines gave the possibility to calculate the neutral ranges and the comfort ranges. A neutral PET (physiological equivalent temperature) range of 13.0~28.6 °C and a comfort PET range of 14.2~32.6 °C were obtained for three seasons. In addition, the relationships between personal (gender and age of respondents) and microclimatic (air temperature, relative humidity, wind velocity, and solar radiation) factors on thermal sensation votes (TSV) and thermal comfort votes (TCV) were evaluated. The results of multiple regression analysis showed that the variables affecting TSV and TCV changed with the season. The findings of this research enhance our understanding of outdoor human thermal perception and can contribute to more friendly outdoor open space design in Shanghai. Full article

(This article belongs to the Special Issue Thermal Comfort in Built Environment)

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16 pages, 5620 KiB

Open AccessArticle

Damage Detection of Steel Truss Bridges Based on Gaussian Bayesian Networks

by Xiaotong Sun, Yu Xin, Zuocai Wang, Minggui Yuan and Huan Chen

Buildings 2022, 12(9), 1463; https://doi.org/10.3390/buildings12091463 - 15 Sep 2022

Cited by 3 | Viewed by 1686

Abstract

This paper proposes the use of Gaussian Bayesian networks (GBNs) for damage detection of steel truss bridges by using the strain monitoring data. Based on the proposed damage detection procedure, a three-layer GBN model is first constructed based on the load factors, structural [...] Read more.

This paper proposes the use of Gaussian Bayesian networks (GBNs) for damage detection of steel truss bridges by using the strain monitoring data. Based on the proposed damage detection procedure, a three-layer GBN model is first constructed based on the load factors, structural deflections, and the stress measurements of steel truss bridges. More specifically, the load factors of the structures are defined as the first-layer network nodes, structural deflections are considered as the second-layer network nodes, and the third-layer nodes of the GBN model are built based on the stress data of the truss elements. To achieve the training for the constructed GBN model, the finite element analysis of the bridge structures under the different load factors is performed. Then, the training of the network is performing by using the maximum likelihood estimation approach, and the optimized network parameters are obtained. Based on the trained network model, the measured load factors and the corresponding stress monitoring data of a limited number of truss elements are considered as input, and the stress measurements of all truss elements of bridges can be accurately estimated by searching the optimized topological information among network nodes. For a steel truss bridge, when the truss elements are damaged, the stress states of the damaged elements will be changed. Therefore, a damage index is further constructed for damage detection of steel truss bridges based on the changed stress states of those damaged elements. To verify the feasible and effective use of the proposed damage detection approach, an 80 m steel truss bridge with various damage cases was conducted as numerical simulations, and the investigation results show that the trained GBN can be accurately used for stress prediction of steel truss bridges, and the proposed damage index with the estimated stress data can be further applied for structural damage localization and quantification with a better accuracy. Furthermore, the results also suggest that the proposed damage detection procedure is accurate and reliable for steel truss bridges under vehicle loads. Full article

(This article belongs to the Special Issue Structural Health Monitoring of Buildings, Bridges and Dams)

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