Simulation Study On Occupant Evacuation Characteristics Under Different Layout Plans

With the advance of economic globalization and the rapid development of science and technology in recent years, the level of urbanization is accelerating, and population is also concentrated more and more serious. In order to meet people’s needs of life, modern buildings have been developing to large-scale volume, complex structure, diverse use function etc. Large-scale buildings are places which usually have high-density populations, it is likely to result in a large number of casualties once occur fire, earthquake and other sudden accidents. Consequently, occupant evacuation in buildings under emergent conditions is expressly concerned by researchers. As the traditional basic research needs to consume a lot of human and material resources and time, computer simulation methods are widely used by modern researchers to study occupant evacuation.Firstly, three unit rooms of different structures were used as the research objects and two cases were considered in which there is respectively one exit and two exits. The effect of the change of exit location and width on occupant evacuation was studied by Pathfinder simulation from occupant evacuation time and evacuation efficiency. Some conclusions were found by simulation analysis of the change of unit rooms’exit width and location when there is only one exit in each room. The changing laws of the total evacuation time and evacuation efficiency are very different with the change of exit location when the structures of unit rooms are different. The total exit flow changes with the increasing of exit width and the total exit flow and exit width can be approximately indicated by a linear increasing function. The simulation study of unit rooms when there are two exits in each room shows:The distance between two exits should be set to the minimum or maximum value when the two exits are symmetrical arrangement in the same side in each unit room. The evacuation rates are larger at this time, which is in favor of evacuation. The difference of two exits’widths should try to take a small value when we choose exits’widths. The greater the total number of staff is, the greater the impact of the difference of two exits’widths on the total evacuation efficiency will be.Secondly, models of building structures with corridor were established with Pathfinder numerical simulation method and the evacuation processes were simulated under different corridor structures in order to research the impact of the respectively change of corridor width, the corridor angle, the number of corridor exit and the total exit width on occupant evacuation when the occupant densities were different. The results show:One exit is more in favor of evacuation than two exits when the total exit widths of corridors are the same and the larger the occupant density is, the larger the superiority will be. The effect of the change of corridor angle on evacuation is influenced by occupant density. Staffs will be concentrated to the inside of corridor corner where there is a shorter evacuation distance when the occupant flows pass corners, which results in congestion of the inside staffs and occupant redistribution. The larger the occupant density is, the more obvious congestion and occupant redistribution phenomena will be. There is a great impact of corner distance on evacuation, the changing lows of evacuation efficiencies with the increase of corner distance are different when the occupant densities are different.Finally, as the plans of two actual rectangle and back to form buildings for example, comprehensive simulation and analysis of occupant evacuation on whole building plans are conducted and some conclusions which are in favor of evacuation and building plan design are obtained.