Emergency evacuation in high-rise apartment building is a challenge for fire safety professionals. Lift evacuation is a controversial issue because the safe operation of lift is not ensured under the existing design and operating conditions. Lifts are not permitted for public evacuation in apartment buildings during fire emergencies as per the provisions of building codes and regulations. However, the concept of using lifts for emergency evacuation has been gaining considerable attention during recent years. The lift evacuation can be considered as an alternative facility if it is efficient, reliable and readily accessible. It can also provide a safer means of evacuation for the aged and disabled persons, who may not be able to evacuate promptly, efficiently and unassisted using the exit stairs during fire emergencies. Moreover, lifts can enable building corporate management to easily and promptly access the fireaffected floor and commence fire fighting. The work on the use of lifts for emergency evacuation was initiated in the early 1990s at the National Institute of Standards and Technology (NIST, USA) in which pros and cons were analysed in order to develop suitable guidelines. This research project examines the feasibility of using lifts along with design modifications as an alternative facility for a safer and more efficient emergency evacuation. The scope of this research is limited to apartment buildings where occupant load is low and fire load is generally confined to dwelling compartment units. This research project analysed the important issues in relation to the use of lifts for emergency evacuation. The issues were divided into three categories: human behavioural response, fire hazards and lift operational mechanism. Output variables relating to human behavioural response were modelled and analysed as a stochastic process. Residents’ choice for using evacuation routes was determined using a survey. The issues of fire hazards (fire, smoke and toxic gases) were analysed for occupant safety under variable conditions using the concept of fire safety index. The issues of lift operational mechanism such as lift malfunctioning due to excessive temperature, electric power failure and water damage were considered for developing probabilistic models. An integrated approach of risk assessment for the issues of human behavioural response and fire hazards (such as ‘decision uncertainty’, ‘panic’, ‘nonfatal and fatal injuries’) was developed based on the Multi-Objectives Decision Analysis method. The results for lift and stair systems were compared and the feasibility of using lift with design modifications was analysed for alternative designs and evacuation strategies. The outcomes of this research have shown that using lifts with a protected lobby for up to one-fourth of the building population (who may be aged and disabled) has huge potential as an alternative evacuation facility with enhanced level of safety. Lifts with protected lobby for one-fourth of the building population showed an improved level of fire safety from exposure to fire effluents. The reliability of lift operational mechanism is also improved in protected lift shafts. Lifts with protected lobby for up to one-fourth of the building population and stairs for up to three-fourth of the building population showed an improved evacuation safety. The risks in combined evacuation systems (protected lifts and stairs) are found to be lower when compared to using stairs or protected lifts. Lifts with double lobby protection (for example, two levels of compartmentation with fire and smoke doors for lift lobby) showed further improvements. This research has proposed alternative designs for lifts and developed models for analyzing evacuation effectiveness based on risks related to human behaviour, fire hazards and operational mechanism. It has shown that a combined use of lifts and stairs has significant advantages. The performance based lift evacuation system is achievable in apartment buildings. These research findings are based on uncertainty analysis, which can be further extended to other types of buildings in the future.

M.Ing. / In the mining industry safety is a primary concern. Especially so when it comes to the large conveyances transporting people, equipment and ore up and down the shaft. Even though it has occurred seldomly, a so-called "slack rope event" - when the conveyance gets stuck in its guides - is extremely dangerous. If the conveyance should become freed it will fall freely until all the slack rope has been taken up and then whiplash. The immense strain could lead to complete failure of the rope or suspension mechanisms. The large deceleration rates experienced could in itself be sufficient to cause serious injury or even death to passengers. A strategy to alleviate this danger, originated by Greenway and Hymers (41), is to have passive energy absorber units in parallel to the suspension mechanism of the conveyance. In the event of an emergency the suspension mechanism will be detached and the absorbers will then be activated, safely absorbing the kinetic energy the conveyance has gained. The dynamic behaviour of the system with and without the energy absorbers in a free fall situation was studied and it was clear that the hazards associated with a slack rope event could be successfully alleviated using the energy absorbers. The question that now presented itself was, which energy absorbing mechanism should be used in this application. An encompassing set of qualifying criteria was subsequently set and after extensive research and evaluation the cyclic plastic bending energy absorber was deemed to be most suitable for this application, as also suggested by Greenway and Hymers (41). The device uses a metal element being bent and unbent while being pulled through a set of rollers. The kinetic energy is transformed to plastic metal deformation and dissipated as low grade heat. Further research was then done on this energy absorbtion device. It revealed a substantial amount of background information and two approximate equations for prediction of the resistive force delivered by the device. It was subsequently attempted to find an analytical solution from first principles, to predict the resistive force and characteristic behaviour of the device. Two solutions were obtained, using different approaches to the problem. A number of experiments were then conducted to study the actual characteristics and behaviour of the device. After manipulation of the results it was found that non-dimensional parameters could be formulated which would make it possible to predict the behaviour of full-scale prototypes using small-scale models. Upon comparing the experimental results with the analytical solutions it was found that the two analytical solutions provide an upper and lower bound to the experimental results. Finite element analysis was also utilized to characterize the behaviour of the device and to attempt to predict the resistive force the device delivers. The finite element models revealed some interesting characteristics of the device and mimicked the behaviour of the actual device. However, the resistive force values obtained, deviated slightly more from the experimental values than the scaling method or the analytical solutions. It is thus possible to predict the behaviour of the cyclicplastic- bending energy absorber by utilizing scaling techniques, analytical solutions or the finite element method. The cyclic-plastic-bending energy absorber has a wide spectrum of applications as it is a very versatile and reliable energy absorber.

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Engineering / It has been said that experimental modal analysis (EMA) "grew to prominence because the engineering community was incapable of properly analyzing the dynamics of commercially significant structures" [24]. The advent of powerful theoretical methods, such as the Finite Element Method (FEM) has not, however, resulted in the demise of EMA. In fact both FEM and EMA have undergone rapid growth and the merging of the two into an effective design and diagnostic tool has had a major impact on the engineering community's approach to dynamics related problems. In this study, the term dual has no mathematical connotations and is used to describe the complementary use of the techniques of EMA and FEM. The mining industry, worldwide, has experienced dynamics related problems in the operation of conveyances in vertical shafts. A study undertaken in South Africa investigated the behaviour of shaft steelwork and skips, resulting in a set of design guidelines for future shaft steelwork designs. This work only investigated the dynamic behaviour of skips. In this project, the ABAQUS and MODEL SOLUTION FEM codes were used to construct models of a. mine cage. An impact modal test was carried ant on the cage, using a GenRad 2515 CAT system, An impact hammer, suitable for exciting large structures, and a strain gauge force transducer were designed and built for the purpose of the test. The natural frequencies and mode shapes obtained from both FEM and EMA are compared by means of the modal assurance criterion (MAC). The test data is used to tune the model to produce accurate results. The model Could then be used (with minimal further test work) for predicting the response of the structure to dynamic loading or the effects of structural modifications. / Andrew Chakane 2020