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1.
Emergency rooms are critical infrastructures that provide acute care and rapid treatment of sudden illnesses and trauma. These life saving services must remain in continuous operation. An internal chemical attack on an emergency room would interrupt these essential services and severely impact the capabilities of the health care professionals and staff. In this paper, a combination of multizone simulation and statistical modeling are used as tools to assess emergency room designs for protection against an internal chemical threat. Design options include: the use of dilution ventilation, additional air handling equipment, gas phase filtration, building segmentation, and a sensor system to improve response time. Protection levels are placed into discrete categories and an ordered probability model (with random effects) is estimated. This model identifies factors, such as the design option, chemical type, elapsed time after chemical release, and the air handling unit’s operational and maintenance costs that significantly influence protection levels. Marginal effects are also computed to measure the impact of these factors on the protection-category probabilities. The results of this study can assist owners, designers, and decision makers by providing a quantitative methodology to assess building designs for protection against chemical threats.  相似文献   

2.
To reduce operating costs, cold storage buildings are being designed with increasing levels of thermal roof insulation. This paper examines the current state of the art in order to estimate average roof insulation requirements in modern cold storage buildings. This research includes both economic and environmental considerations. The added environmental impact of manufacturing thermal insulation is compared to the reduced environmental impact of the building’s cooling load. The cost of purchasing and installing additional roof insulation is also compared to the annual energy savings associated with the increase to establish the most economic insulating level given today’s cost of energy. This paper shows that, from an economic, as well as from an environmental performance perspective, there is a need to design more efficient, sustainable cold storage buildings now.  相似文献   

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Explosive attacks on buildings create a rapid release of energy in the form of a shock wave. Window glass is often the weakest part of a building, breaking at low pressures compared to other building components. Explosion-related injuries caused by glass breakage include eardrum damage, lung collapse, and penetration- or laceration-type injuries from airborne glass fragments which may lead to fatalities. As glass breakage may extend for miles for a large external explosion, reducing glass hazard is an important aspect of blast-mitigation for buildings. Blast-mitigating window products are in their infancy in the United States. Categories of available window retrofit solutions include: window film technologies, mullion and frame upgrades, catch systems, window replacement systems, installation of secondary windows, and/or a combination of these technologies. Installation of daylight film is the least costly but provides the lowest level of protection, while replacing windows is the most costly with the greatest gain in blast protection. Selection of the best window retrofit solution is usually based on a number of design constraints including blast criteria, building constraints—which can be broken down into type of building, maintenance and operability requirements, interior finishes, energy conservation requirements, lifecycle—and finally the retrofit cost.  相似文献   

5.
This study reviews research carried out in the U.K. to understand and improve the robustness of buildings when subject to blast from high explosive bombs. The work concentrates on the performance of ordinary civilian buildings, with particular emphasis on multistory buildings framed in either reinforced concrete or structural steelwork. At that time, some of the data were used to enhance conventional building construction, principally on government buildings, and some were used to aid postwar hardened building construction. The two main U.K. researchers whose work is the basis of this paper (Professor Sir Dermot Christopherson and Professor Lord Baker) identified a number of building weaknesses that led to local or progressive collapse, including connections in steel-framed buildings, as well as detailing weaknesses in reinforced concrete constructions. This paper reviews these features, as well as those that added resilience to bomb damage, with particular emphasis to the use of masonry infill panels in framed buildings. Much of the information on building performance is relevant to today’s engineers engaged in the design of buildings to survive blast from terrorist attacks involving a vehicle-borne improvised explosive device.  相似文献   

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Several hydrometallurgical processes have been studied for the extraction of metals from lean ores utilizing various flow sheet options. Of particular significance is the grade of the ore being treated, the energy consumed and associated costs, options for byproduct recovery, and the relative price of the products. A process scheme needs to be optimized for simultaneously maximizing metal throughput and minimizing the direct operating costs incurred within constraints set for the operating variables. This leads to a multi-objective optimization problem. The range of input grades for raw material, which a flowsheet can handle, needs to be worked out based on an optimization exercise. A lean manganese-bearing resource such as polymetallic sea nodules has been chosen in this article for the development of an optimization approach based on which the input raw nodules grades are to be treated by a particular flowsheet. Only the chemical consumption costs have been adopted in this article as a measure of direct operating costs. A linear simulation model for the flowsheet has been developed, keeping a set of design parameters constant. The solutions generated by using a sequential modular approach become inputs to an optimization procedure based on a multi-objective genetic algorithm belonging to the differential evolution family. The variables considered in the optimization task are the grade of nodules and reactivity of different species inside the reactor. A nickel equivalent (t/h function) has been suggested as a measure of productivity, as it indirectly enhances the input manganese ore grade through a price ratio effect. This productivity function was maximized with the simultaneous minimization of direct chemical costs. Pareto optimal solutions were generated with grades of nodules and reactivity in the leach reactor as decision variables. The effect of the price ratio on the Pareto optimal solutions was also investigated. The various cases investigated clarifies the methodology for choosing an appropriate ore grade range for a given process flowsheet. Appropriate decisions regarding the nature of raw material to be used for a given flowsheet are then found on the basis of the Pareto optimal solutions.  相似文献   

8.
The current International Building Code (IBC) allows wood-frame (i.e., light-frame wood) construction to be three stories high or four stories high if sprinklers are included in the design. Several jurisdictions within the United States have opted to allow four and five stories if sprinklers are present. This paper presents a comprehensive numerical analysis of a six-story wood-frame building designed on the basis of the 2006 IBC methodology and a building designed by using the direct-displacement design (DDD) approach. The objectives of the design methods are different and are explained herein. Incremental dynamic analysis (IDA) was used to numerically investigate the response of the buildings on the basis of two criteria: the peak interstory drift and the building’s base shear capacity. Gypsum wall board was included in both models, but exterior finishes (e.g., stucco) were not.  相似文献   

9.
Seismically induced settlement of buildings with shallow foundations on liquefiable soils has resulted in significant damage in recent earthquakes. Engineers still largely estimate seismic building settlement using procedures developed to calculate postliquefaction reconsolidation settlement in the free-field. A series of centrifuge experiments involving buildings situated atop a layered soil deposit have been performed to identify the mechanisms involved in liquefaction-induced building settlement. Previous studies of this problem have identified important factors including shaking intensity, the liquefiable soil’s relative density and thickness, and the building’s weight and width. Centrifuge test results indicate that building settlement is not proportional to the thickness of the liquefiable layer and that most of this settlement occurs during earthquake strong shaking. Building-induced shear deformations combined with localized volumetric strains during partially drained cyclic loading are the dominant mechanisms. The development of high excess pore pressures, localized drainage in response to the high transient hydraulic gradients, and earthquake-induced ratcheting of the buildings into the softened soil are important effects that should be captured in design procedures that estimate liquefaction-induced building settlement.  相似文献   

10.
Due to the lack of data and experience with designing buildings for a bioterrorism hazard, it is important for civil engineering professionals to understand both the way that risk is currently accounted for in the design of a building for a bioterrorism hazard and the methods for analyzing risks to buildings that can be borrowed from risk analysis professionals. This paper provides a literature survey of four subject areas dealing with the risk analysis of bioterrorism applied to buildings: (1) perception of the risk of bioterrorism; (2) risk analysis of bioterrorism; (3) risk management of bioterrorism risks; and (4) risk communication of bioterrorism risks, and includes an example of a simple risk analysis process for a hypothetical building. Bioterrorism presents building design engineers with new challenges. It is a very unpredictable hazard, and very little data exist to guide building designers and decision makers in protecting buildings from this hazard. Designing a building with bioterrorist attacks in mind involves many different disciplines, including, for example, structural, mechanical, and electrical engineering, architecture, landscape architecture, security design professions, and law enforcement. Large consequences are possible in the event of a successful attack, and many building design engineers have little or no experience with defending against a bioterrorist attack. It is important that a reasonable process for analyzing and dealing with these risks be established, and that the process include issues of risk perception and communication within the risk analysis framework.  相似文献   

11.
High-performance green buildings require close integration of building systems with a special focus on energy, daylighting, and material analysis during their design processes. Design process modeling and use of visualization tools can facilitate better communication and collaboration between team members; hence better integration in the design process. This paper presents a case study of the integrated design process of an Early Childhood Learning Center as performed by a team of university students and faculty. A process modeling approach of key decisions, required consultants, and virtual prototypes of the building was used during the design development stages of the case study. This case illustrates the use of process modeling and visualization tools to provide an accurate building information system for integrated teams. Through this experience, process modeling and visualization tools were found to be useful mechanisms to achieve high performance design goals and minimize design process waste.  相似文献   

12.
It is the cost estimator’s task to determine how the building design influences construction costs. Estimators must recognize the design conditions that effect construction costs and adjust the project’s activities, resources, and resource productivity rates accordingly to create a cost estimate for a particular design. Current tools and methodologies help estimators to establish relationships between product and cost information to calculate quantities automatically. However, they do not provide a common vocabulary to represent estimators’ rationale for relating product and cost information. This paper presents the ontology we formalized to represent estimators’ rationale for relating features of building product models to construction activities and associated construction resources to calculate construction costs. A software prototype that implements the ontology enables estimators to generate activities that know what feature requires their execution, what resources are being used and why, and how much the activities’ execution costs. Validation studies of use of the prototype system provide evidence that the ontology enabled estimators to generate and maintain construction cost estimates more completely, consistently, and expeditiously than traditional tools.  相似文献   

13.
The rapid progress in computational hardware and software has brought about advanced capabilities enabling more accurate modeling of structures and better understanding of their lifetime behavior. Unfortunately, research in life-cycle performance prediction and service-life estimation of bridges has not fully caught up with the impressive advances in today’s technology, and has not taken enough advantage of the power offered by these advances. In this paper, a computational methodology for the life-cycle prediction and service-life estimation of bridges using advanced modeling tools and techniques is presented. The methodology employs incremental nonlinear finite element analyses, quadratic response surface modeling using design of experiments concepts, and Latin hypercube sampling, among other techniques. The methodology is illustrated on an existing bridge in the state of Wisconsin.  相似文献   

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Several alternatives are being attempted to obtain the sustainable residential building, based on the acceptable level of environmental impact and socio-economic characteristics of residential building. These criteria are in conflict each other, thus it is very difficult to assess or find the sustainable residential building. This paper presents a methodology of the assessment for residential building that is intended to assist the decision making for the building planners or practitioners. The results show that this approach can effectively work for the quantitative evaluation and selection of the best alternative of the residential buildings considered, especially when conflict relation exists. This approach allows the planner or construction companies to test design strategies against different sets of criteria.  相似文献   

16.
Transmission expansion planning has become a central challenge in the design of competitive electricity markets. The underlying optimization/decision problem exhibits a high level of complexity, being nonconvex, dynamic, and nonlinear, with multiple objective functions and a wide range of uncertainties. In this paper we propose a methodology for handling the expansion problem that involves a novel adaptation of an iterative optimization method based on response surface models already used successfully in the design and manufacture of integrated circuits. It is implemented in a distributed environment using Web services, and is validated and compared with a genetic algorithm based methodology. An application of the proposed methodology to the Chilean Central Interconnected System is then presented and analyzed. The results demonstrate its potential in the fields of risk analysis and decision support systems in power markets.  相似文献   

17.
Medical records provide essential information for evaluating a patient’s health. Without them, it would be difficult for doctors to make accurate diagnoses. Similar to diagnoses in medical science, building health management also requires building medical records for making accurate diagnoses. At later stages of a building’s life cycle, when the budget is limited, organizations responsible for building repairs and maintenance are unable to digitalize building health diagnoses and keep complete medical records of buildings; as a result, maintenance crews usually cannot fully understand buildings’ overall health conditions and their medical histories, which may result in erroneous diagnoses directly or public safety dangers indirectly. Using the problem-oriented medical record adopted for the medical diagnosis of human diseases, this paper designs a building medical record (BMR), which allows simple electronic archiving, and evaluates its practicability with a case study of school buildings. The purpose of a BMR is to enable maintenance engineers (building doctors), building managers, and contractors of school buildings to have low-cost access to required information for making complete evaluations and maintenance suggestions for buildings.  相似文献   

18.
This paper presents an analysis of current conceptual design processes for high-rise buildings. We synthesize a method to document and measure these processes and use it to analyze data from several case studies and a survey of leading architectural and engineering design firms. We describe current high-rise conceptual design process in terms of the following: design team size, composition, and time investment; clarity of goal definition; number and range of design options generated; number and type of model-based analyses performed; and the criteria used for decision making. We identify several potential weaknesses in current design processes including lack of clarity in goal definition and a low quantity of generated and analyzed options. We argue that potentially higher performing designs are being left unconsidered and discuss the potential reasons and costs.  相似文献   

19.
With increasing complexity in the building construction trend and the advancement of building material technology, more building materials and substitutes have evolved and been adopted for use to function together in a building that is supposed to maintain its technical performance during its intended working life. Condition surveys of 450 buildings, face-to-face interviews, and workshops were conducted with industry specialists, to examine the behavior of materials used in facades and wet areas in tropical climates and their estimated costs of maintenance. This paper presents an indicative computational method for the durability of building materials for fa?ades and wet areas in the tropics. Total operations and maintenance costs of the identified materials are also included to provide suggestive maintenance expenditure over the materials’ service life. Natural stone was preferred as a more durable fa?ade material while ceramic and homogeneous tiles proved more economical for wet areas.  相似文献   

20.
A widely recognized theme of construction economics suggests that the cost of construction per square meter increases as building height rises. However, over a number of years, research conducted regarding the height and cost issue has established a classic relationship between the two factors which can be represented by a U-shaped curve. This paper describes the study of the height-cost relationship of high-rise residential buildings in Shanghai in terms of the total construction cost and elemental costs while considering the context and commonality of buildings. This research was developed as an extension of the previous work, which examined data for buildings in Hong Kong. Initial findings indicate that the curves illustrating the relationships between height and cost of residential buildings in Shanghai and Hong Kong exhibit different profiles. The dissimilarities indicate that different sets of criteria should be applied in the judgment of height that affects cost in different locations. In terms of elemental costs, the findings suggest that there are differences in the way these costs react to changes in the building height.  相似文献   

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