Study On Fire Field Simulation And Crowd Evacuation In Cylinder Roof Gymnasium

With the development of social economy and technology,large-span buildings have been widely used because of their vast interior space and beautiful architectural composition.The structure of cylinder shells has become the important structural form,which has large rigidity and saving of materials.This kind of building,as a place with high concentration of people and capital,is easy to cause heavy losses of life and property when the fire smoke spreads quickly and the evacuation distance is long.Therefore,it is practical to study the process of fire development and evacuation for space structures.In this paper,the cylindrical space structure is selected,and the fire field simulation based on FDS software is used to analyze the gas flow characteristics and the distribution of the risk parameters.Based on the Pathfinder software,the evacuation simulation is carried out to analyze the behavior rules.The main contents are as follows:First,the theory and use characteristics of the FDS software,the post-processing program Smokeview and the integrated software Pyro Sim of the two are introduced.Based on FDS,the temperature field of large space fire is simulated and compared with the experimental data in reference,so as to verify its reliability.Based on FDS,a single layer cylindrical reticulated shell model is established with the change of the parameters such as the fire power,the ratio of rise to span and the ignition location.The influence of the parameters on the temperature field is studied through the induction and analysis of the temperature-time curve of different paths at the roof,the representative temperature cloud images in the space and the whole temperature curve of the measuring points.Secondly,a full size fire model of a small gymnasium is established with reference to relevant engineering materials and specifications,and the models with different ignition location and natural ventilation are simulated.The smoke spread process and the parameters for measuring the fire risk are compared and analyzed,such as the temperature field,the visibility and the CO concentration.Finally,the criteria for the safety evacuation in the fire field are set,and the design principle and use characteristics of the Pathfinder software are introduced.Based on this,the evacuation model of the gymnasium is established and the relevant parameters of the personnel are set up,such as the personnel load,the composition type,the walking speed,the reaction time and so on.The fire simulation results are coupled with the evacuation of personnel,and the evacuation conditions under different conditions are analyzed,and the safety judgement and suggestions are given.