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Long-span, single-layer spatial grid structures are widely used in public buildings. The progressive collapse of such structures could cause great losses of property and human life. To accurately capture the performance of a structure in progressive collapse, an efficient dynamic behavior analysis should be conducted. In this paper, a multi-degree-of-freedom simplified model was established to represent the progressive-collapse dynamic behavior of single-layer spatial grid structures. Based on the simplified model, two dynamic behavior modes were identified: ordinary and specific dynamic behaviors. In ordinary dynamic behavior, the dynamic effect caused by local failure cannot be transmitted, and the displacement responses of the joints in the failure area are symmetrically distributed based on the final equilibrium states, with the gradual attenuation of the dynamic effect. For the specific dynamic behavior, the dynamic effect is transmitted and a disorganized response of single-layer spatial grid structures occurs. Furthermore, the dynamic progressive-collapse behaviors of six full-scale typical domes were analyzed with a verified numerical simulation. The results indicate that a multi-degree-of-freedom system is necessary for accurately reflecting the dynamic behavior of single-layer spatial grid structures. The middle position between vertex and supports can be defined as the important area of reticulated domes, where a member's failure would have a significant effect on structural performance. If a specific dynamic behavior plays a dominant role in the overall structure, the progressive-collapse resistance may be improved for a single-layer spatial grid structure. [ABSTRACT FROM AUTHOR]

Buildings in the United States are responsible for 72% of the nation’s electricity consumption, 39% of energy consumption, 39% of carbon dioxide emissions, and 13% of potable water consumption. These significant energy and water consumptions and their carbon emissions contribute to global warming, ozone depletion, and air pollution. To reduce these negative impacts of buildings and improve their economic performance, there is an increasing demand for integrating sustainable measures in public buildings such as energy-efficient lighting; motion sensors for interior lighting; motion sensors for lighting of vending machines; motion sensors for exhaust fans; solar daylight tubes; energy-efficient HVAC systems; thermal-pane glass; vestibule entrances; energy-efficient hand dryers; solar photovoltaic systems; and water-saving toilets and urinals. Despite the recent increase in the availability of these sustainable building measures and technologies, there is a pressing need to analyze the economic and greenhouse gas (GHG) emission effects of implementing these measures in existing buildings. This paper presents an economic and GHG emission analysis of implementing various sustainable measures in six highway rest area buildings. The economic analysis was performed based on the initial upgrade costs, maintenance costs, operational costs, energy and water savings, discount rate, and escalation in energy rates. The GHG analysis was conducted based on the generated building emissions of carbon dioxide, nitrous oxide, and methane. The findings of the conducted economic and GHG emission analysis showed promising results with feasible implementation and return on investment for various sustainable-building measures. In addition, the implementation of all the analyzed measures in all rest area buildings simultaneously showed promising return on investment with payback periods ranging from 6.9 to 11.3 years. The findings of this research paper can aid decision-makers and building owners to estimate the costs and benefits for implementing various sustainable-building measures in public buildings, as well as to prioritize the implementation of these measures based on their available budgets, reduction in operational costs and GHG emissions, and payback periods. [ABSTRACT FROM AUTHOR]

This paper presents the integral lifting and seismic isolation retrofit of the great hall of Nanjing Museum, a 78-year-old cultural and historical building. Due to the need for extension, the great hall of the Nanjing Museum needed to be lifted . The total building area for lifting was , with a total of 161 lifting points, which made this project quite challenging and also the largest done to date. Moreover, seismic isolation retrofit was utilized to improve the seismic performance of the translocated building. Details of the integral lifting and the seismic retrofit are presented in this paper, which include (1) the load underpinning system, (2) the spatial strengthening truss system, (3) the lifting control system, and (4) the base isolation using laminated rubber isolators. The entire lifting system performed well, and the main construction was finished within 5 months. Seismic time-history analyses were further performed to evaluate the effect of the seismic isolation. It was observed that the seismic responses of the museum were significantly reduced after retrofit. [ABSTRACT FROM AUTHOR]

This paper presents a study of selection of procurement method in building maintenance management for public universities in Malaysia through the use of multiple criteria decision making (MCDM), particularly the analytic hierarchy process (AHP). There are many different types of procurement methods that have been developed to overcome the weaknesses of the existing procurement method and to meet the range of service requirement. The decision makers are faced with challenges when it comes to selecting the most appropriate procurement method for a specific building as different types of procurement methods suit different types of projects. This research seeks to investigate the current practices of the available procurement methods for building maintenance work in public universities and identify the procurement selection criteria to develop an effective decision-making framework. A questionnaire survey was conducted among 20 public universities in Malaysia with 85% response rate to identify and validate two important components for the development of a decision-making framework: the possible assessment criteria and the alternatives available for selection. The finding of this research proves that the selection of procurement methods by university organizations is neither strategic nor systematic as there is no guidance available for the decision maker to rely on in order to select the most appropriate procurement strategy. It is vital to develop a systematic approach that can assist maintenance personnel in making a decision on selecting procurement methods for a particular building. [ABSTRACT FROM AUTHOR]

Despite the importance of the condition assessment (CA) stage in the asset management process, literature review reveals that there are some drawbacks in the current practices. The objective of this paper is to develop a condition assessment model for buildings. A new building asset hierarchy is proposed in which the space is the principle element of evaluation. Physical components within a space are categorized into four main categories. Data are collected from experts via questionnaires to assign relative weights to models' attributes using both the analytical network process (ANP) and the analytical hierarchy process (AHP) techniques. Finally, the multi attribute utility theory (MAUT) is used to calculate the physical condition assessment of spaces and the entire building. The developed model is applied to a case study of an educational building located in Montreal. Results of the model are compared with the calculated results by the building facility management team. Many lessons are learned from the study; among the most significant findings is the importance of building categories and subcategories that differ according to space type. This model will assist owners and facility managers in the condition assessment phase during the asset management process by applying several tools and techniques to provide an accurate condition assessment. [ABSTRACT FROM AUTHOR]