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Lin, Y-S (1996) Optimal design and probabilistic evaluation of fire egress systems, Unpublished PhD Thesis, , Duke University.
- Type: Thesis
- Keywords: failure; optimization; reliability; evacuation; programming; safety; linear programming; probability; Monte Carlo simulation; simulation; architect
- ISBN/ISSN:
- URL: https://www.proquest.com/docview/304253463
- Abstract:
In this research three models for determining the optimal design of building egress systems are presented. In addition, a Monte Carlo simulation model is presented to probabilistically evaluate the performance of optimal egress designs. To model the reliability of a building egress system, a life safety model concerning the time of smoke inundation and occupants evacuation is formulated. The probability that total evacuation time exceeds the time for smoke inundation is modeled as a chance constraint for the nonlinear chance constraint optimization model in order to plan acceptable egress strategies. To plan the optimal egress design and evaluate the efficiency of a building egress system, two nonlinear optimization models that minimize rental space loss are presented. To illustrate these models, several examples are presented. To model the reliability of egress systems, an example contingent on probabilistic heat release rate and occupant load is presented. Monte Carlo simulation is used to select randomly the related state variables for the evacuation process. Model results produce comparable designs, provide the architects and fire protection engineers with a measure of the probable egress performance and illustrate the tradeoff relationship between the rental loss and the probability of egress system failure. To achieve the optimal egress system design, an example of a four floor building with specified design occupant load, number of stairs and stair width is presented to evaluate the efficiency of building egress systems. Another example, a two floor building, is formulated to determine the optimal widths of means of egress. These two nonlinear optimization models are solved by using the linear programming package XMP. Model results demonstrate the efficiency of the staircase design and the optimal design of egress systems, and illustrate the trade-off between the loss and evacuation time. A simulation model is also performed for evaluating the design obtained by flow- and capacity-based optimization model. Using the stochastic simulation model to evaluate the performance of the optimal design for a pre-set design evacuation time of 10 minutes, the probability of failure is approximately equal to 0.00528.