"Performance based methodologies are becoming increasingly common in fire safety due to the inability of prescriptive codes to account for every architectural feature. Fire Sprinkler suppression systems have long been used to provide property protection and enhance life safety. However, very few methodologies exist to account for the impact of sprinkler sprays on fire scenarios. Current methods are extremely complicated and difficult to use as an engineering tool for performance based design. Twenty four full scale fire tests were conducted at Tyco Fire Suppression & Building Products Global Technology Center to determine a simple method for accounting for the impact of a single residential sprinkler on fire induced doorway flows. It was found that a spraying sprinkler reduced the mass flows at the doorway while maintaining two stratified layers away from the sprinkler spray. The mass flow reduction was consistent and could be predicted through the use of a simple buoyancy based equation. The current study suggests that the buoyancy equation can be altered through the use of a constant cooling coefficient (equal to 0.84 for a Tyco LFII (TY2234) sprinkler) based on the test results reported in this paper. This study is a proof of concept and the results suggest the methodology can be applicable to similar situations."

"This research effort addresses key challenges associated with the technical review and acceptance of performance-based design approaches to fire safety engineering through development of a decision support framework and associated tool. Such design approaches seek to confirm that the overall fire safety system, which includes the building and its protective features, meets a set of fire safety objectives established by relevant stakeholders, and this confirmation is achieved through fire safety analysis, or the application of analytical and computational tools and methods. While the current approach to performance-based fire safety analysis relies on guidelines and standards, these rather generic, process-oriented documents do not provide fire protection engineers (FPEs) sufficient guidance to address critical elements of the analysis process in a systematic, consistent and technically adequate manner. Should a fire safety analysis contain technical deficiencies, then it becomes less clear that the design solution being proposed truly achieves the desired fire safety objectives. Moreover, project stakeholders, including the authority having jurisdiction (AHJ), may lack the necessary qualifications, expertise, or design intimacy to, suitably and reliably, identify and challenge deficient analyses. As a result, the current approach to fire safety analysis and its quality assurance has led to large variations in analysis quality and consequently levels of delivered performance. With no existing equivalent, a decision support framework is proposed that will assist the AHJ and FPEs in determining whether a fire safety analysis is of sufficient technical adequacy to support decision-making, regulatory or otherwise. Additionally, a decision support tool is developed to provide measures of confidence regarding an analysis’s conclusions and assist in identifying those aspects of the analysis most requiring corrective action. Lastly, while developed to address performance-based design approaches to fire safety engineering, the framework may easily be adapted to similar approaches in other fields of engineering, or more generally, applications that make use of process-oriented, analysis-driven design."

Review of decades of worldwide experience using standards, codes and guidelines related to performance-based fire protection design for buildings has identified shortcomings in the interpretation, application and implementation of the performance-based design process, wide variation in the resulting levels of performance achieved by such designs, and several opportunities to enhance the process. While others have highlighted shortcomings in the past, as well as some ideas to enhance the process, it is proposed that a more fundamental change is needed. First, the political and technical components of the process need to be clearly delineated to facilitate better analysis and decision-making within each component. Second, the process needs to be changed from one which focuses only on fire safety systems to one which views buildings, their occupants and their contents as integrated systems. In doing so, the activities associated with the normal operation of a building and how they might be impacted by the occurrence of a fire event become clearer, as do mitigation options which account for the behaviors and activities associated with normal use. To support these changes, a new framework for a risk-informed performance-based process for fire protection design is proposed: one which is better integrated than current processes, that treats a fire event as a disruptive event of a larger and more complex "building-occupant" system, and that provides more specific guidance for engineering analysis with the aim to achieve more complete and consistent analysis. This Ph.D. Dissertation outlines the challenges with the existing approaches, presents the "building-occupant" system paradigm, illustrates how viewing fire (or any other hazard) as a disruptive event within an holistic "building-occupant" system can benefit the overall performance of this system over its lifespan, and outlines a framework for a risk-informed performance-based process for fire protection design. Case studies are used to illustrate shortcomings in the existing processes and how the proposed process will address these. This Dissertation also includes a plan of action needed to establish guidelines to conduct each of the technical steps of the process and briefly introduces the future work about how this plan could be practically facilitated via a web-platform as a collaborative environment.

In the United States design for fire safety follows a prescriptive code-based approach. Building codes detail the types of construction materials, assemblies, and fire suppression systems that are required for various building types. This prescriptive method has prevented structural engineers from exposure to performance-based design approaches for fire safety. The motivation for this thesis was to increase the awareness of the structural engineering field to the concepts behind structural design for fire safety. Extensive research has been published on the performance of structural steel in fire conditions, and simplified design tools already exist to describe its behavior. Such tools do not exist for reinforced concrete structures. Research on concrete has been more focused on material properties rather than structural performance. This thesis presents a simplified design tool which assesses the fire performance of reinforced concrete. An Excel-based spreadsheet application was developed for thermal analysis of concrete slabs. It accounts for different aggregate types, slab thicknesses, and fire exposures. Several analyses were performed with the spreadsheet application to examine the affect slab thickness and aggregate types have on the fire performance of concrete slabs in standard and natural fires. The results were compared with published test data and finite element software simulations to benchmark the accuracy of the proposed tool. Furthermore, methods for the design of reinforced concrete slabs in fire conditions are presented.

No description available.

The model building and fire codes in Canada permit prescriptive-based design and performance-based design approaches. Within this regulatory framework, prescriptive-based designs are attributed objective and functional statements to qualify the level of fire protection and life safety required. Performance-based designs, or alternative solutions to prescriptive-based designs, must be demonstrated to achieve at least an equivalent level of performance as the prescriptive requirement based on evaluation of each associated objective and functional statement. Due to the qualitative performance descriptions available, the current system for developing and reviewing alternative solutions is vulnerable to the acceptance of over-designed or under-designed life safety and fire protection measures in buildings. The objective of this thesis is to establish a method to compare the performance of alternative solutions with prescriptive design requirements on a quantitative basis. This thesis generates eight objectives for a fire risk analysis tool to address the challenges identified in the building regulatory industry. Based on review of existing techniques, a new fire risk analysis framework is developed. The Quantitative Design Decision (QDD) method, integrates risk analysis with quantitative decision assessment techniques to facilitate application-specific quantification of performance objectives and to aid evaluation of performance-based designs. The method utilizes an iterative three-stage structure. To demonstrate the application of the QDD method, a case-study simulation has been conducted. The case-study provides an evaluation of alternative designs to the prescriptive requirements for explosion-relief ventilation in rooms housing flammable vapour producing operations. The case study supports the conclusion that QDD achieves the eight objectives set out in this thesis. For validation, the QDD method must be applied to a wider variety of practical design challenges and it is recommended that the results be considered in conjunction with live fire test data to verify key aspects of the performance decisions generated. Future work should include evaluation of Delphi technique application in the Design Decision Stage of the QDD method. It is proposed that the method developed can be extended for use as a general performance-based design tool.

The model building and fire codes in Canada permit prescriptive-based design and performance-based design approaches. Within this regulatory framework, prescriptive-based designs are attributed objective and functional statements to qualify the level of fire protection and life safety required. Performance-based designs, or alternative solutions to prescriptive-based designs, must be demonstrated to achieve at least an equivalent level of performance as the prescriptive requirement based on evaluation of each associated objective and functional statement. Due to the qualitative performance descriptions available, the current system for developing and reviewing alternative solutions is vulnerable to the acceptance of over-designed or under-designed life safety and fire protection measures in buildings. The objective of this thesis is to establish a method to compare the performance of alternative solutions with prescriptive design requirements on a quantitative basis. This thesis generates eight objectives for a fire risk analysis tool to address the challenges identified in the building regulatory industry. Based on review of existing techniques, a new fire risk analysis framework is developed. The Quantitative Design Decision (QDD) method, integrates risk analysis with quantitative decision assessment techniques to facilitate application-specific quantification of performance objectives and to aid evaluation of performance-based designs. The method utilizes an iterative three-stage structure. To demonstrate the application of the QDD method, a case-study simulation has been conducted. The case-study provides an evaluation of alternative designs to the prescriptive requirements for explosion-relief ventilation in rooms housing flammable vapour producing operations. The case study supports the conclusion that QDD achieves the eight objectives set out in this thesis. For validation, the QDD method must be applied to a wider variety of practical design challenges and it is recommended that the results be considered in conjunction with live fire test data to verify key aspects of the performance decisions generated. Future work should include evaluation of Delphi technique application in the Design Decision Stage of the QDD method. It is proposed that the method developed can be extended for use as a general performance-based design tool.

This thesis investigated the potential advantages and disadvantages of high performance structures by comparing the financial and environmental impacts of a performance based four-story office building to one designed to meet minimum code-level requirements. To generate a comparison, the lateral system of a four-story structure utilizing buckling restrained braced frames was designed to meet code-level requirements per the American Society of Civil Engineers’ Minimum Design Loads for Buildings and Other Structures (ASCE 7-05) and again to meet the immediate occupancy criteria defined by ASCE 41-06 Seismic Rehabilitation of Existing Buildings. The following was then performed: Test the structural performance of both buildings using simulated code-level and maximum considered earthquakes Develop construction costs of both structures using RSMeans Square Foot Cost and Construction Cost Data Determine the financial benefit associated with the upgraded structure by subjecting both structures to a suite of earthquakes Calculate the carbon footprint generated during each building’s construction. The final project costs for the code level and immediate occupancy structures were $27.43 million and $27.93 million respectively, resulting in an upgrade cost of $500,000 or roughly 1.8% of the overall project cost. The upgrade cost was then input in FEMA’s Benefit-Cost Analysis, where it found the upgrade cost resulted in an annual savings ranging from $43,000 to $98,000 over the building’s 50-year life cycle. The carbon footprints were generated using BuildingScope, which relies on volumetric quantities of construction materials. The final models resulted in a carbon footprint of 7890 CO2 eq and 7940 CO2 eq for the code level and immediate occupancy structures respectively, showing favor for the structure utilizing fewer materials. Although the additional materials used in the immediate occupancy structure resulted in a slightly larger carbon footprint, the added capacity will decrease damages, resulting in an overall reduction of energy generated during the building’s life cycle.

Post-tensioned timber buildings utilise a new construction technique developed largely as part of research undertaken at the University of Canterbury. Timber buildings are constructed using an engineered timber product, such as laminated veneer lumber (LVL), and then stressed with post-tensioned unbonded high-strength steel tendons. The tendons apply a compressive stress to timber members to create a ductile moment resisting connection between adjacent timber members. The major benefit of post-tensioned timber buildings is a significantly improved structural performance. As timber is a combustible material there is a perceived high fire risk in timber buildings. While timber buildings can be designed to perform very well in fire, a design guide for the fire safety design of post-tensioned timber buildings has not been previously developed. Furthermore, previous research has found that post-tensioned timber box beams may be susceptible to shear failure in fire conditions. This research investigated the fire performance of post-tensioned timber buildings. A design strategy for the fire performance of post-tensioned timber buildings was developed in conjunction with a simplified calculation method for determining the fire resistance of post-tensioned timber structural members. The fire performance and failure behaviour of post-tensioned timber box beam was also specifically investigated, with special focus given to the shear performance of box beams. A full scale furnace test of a LVL post-tensioned LVL box beam was conducted at the Building Research Association of New Zealand (BRANZ). Four further full scale tests of LVL box beams were conducted at ambient temperature at the University of Canterbury structural laboratory. Through this research two distinct strategies for the fire design of post-tensioned timber structures were developed. The first strategy is to rely on the residual timber of the members only. The second strategy considers specific fire protection of the post-tensioning system, which can then be used to contribute to the fire resistance of the member. The results of the full scale tests showed good agreement with the proposed the simplified calculation method. It was also determined that shear failure does not need to be specifically considered other than performing strength checks as for other design actions.

In the rapidly growing field of CFD-calculations (Computational Fluid Dynamics), companies and organizations are bringing forth new tools, tools that display an image of a given fire scenario. These tools are developed because they provide time efficiency as well as a sustainable economic approach. Another useful tool is analytical solutions, these analytical solutions serve the same purpose as CFD-modeling, providing results of a given scenario. The purpose of this thesis was to simulate a fire plume with two different CFDprograms and compare the gas temperature from each simulation with a full-scale test. Also, analytical solutions were used to perform the same comparisons. Four different calculation models were utilized to obtain results. The CFD-programs were FDS (Fire Dynamics Simulator) and FireFOAM. The analytical solutions were performed using McCaffrey´s plume equation and Eurocode solutions for localized fire temperatures. FDS is a very well documented program, due to this, problems that arose were easily fixed. The structure of FDS enables the user to maneuver the program easily. SmokeView was used to visualize the simulation. FireFOAM is written in C++ and is operated through the command prompt. The structure of the program was time-consuming to understand mainly because of two reasons, primarily because the authors lack of knowledge in coding in C++, and second because of the LINUX environment. Moreover, the process of working in FireFOAM was mostly through trial and error. On some occasions, issues arose that could be solved by communication with other CFD users at CFD-Online. When major problems occurred, regarding the code or other CFD issues, Johan Anderson at RISE Research Institutes of Sweden guided us through most of these problems and enabled us to move forward with the work. ParaView was used to visualize the simulation, and Excel was used to evaluate the temperature data from the FDS- and FireFOAM simulations. For the calculations in FDS and FireFOAM, a sensitivity analysis was performed to see which grid size presented best results in each program. A grid size of 5 cm, 10 cm, and 20 cm were applied in FDS, and in FireFOAM the grid dimensions were set to 5 cm and 10 cm. The results showed that 5 cm was the most appropriate grid size for both programs. It would have been more favorably to simulate with several different grid sizes, to further strengthen the grid analysis. Though, due to the time frame of the thesis, further simulations were not performed. Calculations were repeated for the same scenario only with a lower HRR (Heat release rate). An extensive sensitivity analysis was conducted for FDS in the form of two different simulations. One simulation where HRR was the same as the full-scale test but with twice the area of the burner. In the second simulation, the same area was used on the burner as the fullscale test, but with half the HRR. Results from the analytical solutions were easy to achieve; however, the model has some limitations regarding calculations within the flame region. The estimated gas temperature, using FDS, aligns well with the full-scale test. The temperatures analyzed from FireFOAM deviated in general through the flame region and reached unreasonable high temperatures close to the ceiling. Since the analytical solutions were based on different conditions compared to those applied in the full-scale test, it was expected that the results should deviate. However, McCaffrey plume equations can still be used to give an approximate picture of scenarios similar to that of the full-scale test, and the same applies to Eurocode solutions for localized fire temperatures. Analysis of the results shows that FDS can be used to simulate similar scenarios. FireFOAM simulates a gas temperature that is overestimated within the flame region. One of the reasons for this was due to the grid size since the sensitivity analysis III showed that a refined grid size resulted in more correct temperature value, the reason for not simulating with a more refined grid size was due to the restricted time frame of this thesis. FireFOAM is, at present, recommended for researchers who wish to use the code for specific purposes. Therefore, given the same premises, FireFOAM is not recommended for the standard fire safety analysis.