Research On Building Fire Evacuation Path Planning Based On BIM And Optimized Ant Colony Algorithm

With the improvement of urban construction level,the complexity and density of buildings have undergone a qualitative leap.With the rapid development of urban large space buildings,it also brings new challenges to the fire fighting and safe evacuation of building fires.In the event of fire,how to make emergency personnel more safe and effective evacuation in large space building with complex structure is a major problem of building fire evacuation.Based on the above problems,this paper mainly studies the evacuation path planning of large space buildings,and uses BIM Technology to establish the building 3D information model as the fire simulation scene,so as to realize the unification of the simulation scene and the actual building.And combined with the optimized ant colony algorithm to calculate the optimal evacuation path,and finally through the secondary development technology of Revit and webgl technology to achieve the visualization of evacuation path.The main research work of this paper is as follows:First,Building fire smoke prediction model based on BIM model is constructed.This paper analyzes the subjective and objective factors that affect the evacuation in building fire environment,and determines the key factors affecting the evacuation efficiency.Taking BIM model of building entity as fire simulation scene,the prediction model of fire site temperature and smoke concentration is established by using Pyrosim fire dynamic simulation software.Three aspects of fire temperature,CO concentration and smoke visibility were simulated and collected,which provided theoretical basis and data basis for the formulation of optimal evacuation path planning.Secondly,The optimization method of evacuation route based on improved ant colony algorithm is studied.The advantages and disadvantages of ant colony algorithm in path planning are analyzed,and the algorithm is optimized.In the aspect of heuristic function,the concept of equivalent length is proposed to replace the geometric length in the traditional algorithm as the heuristic function;in the pheromone updating strategy,the pheromone evaporation factor is dynamically adjusted to optimize the pheromone update strategy,which improves the global search ability and computational efficiency of the algorithm.Finally,simulation experiments are used to verify the algorithm.The improved algorithm effectively overcomes the stagnation phenomenon and improves the calculation efficiency of evacuation path optimization.Thirdly,The visual realization method of building fire evacuation path is studied.Using the secondary development technology of Revit and webgl technology,the building fire evacuation management system is built,and the 3D reconstruction of building information model and the visualization of evacuation path are realized.The case building is applied to the system to simulate the evacuation path.