Building Fire Simulation And Safety Analysis Based On BIM

The traditional fire simulation method has a low degree of information and low data utilization rate.In recent years,BIM technology has been developed rapidly due to the improvement of computer performance.This paper studied how to apply BIM technology to building fire simulation and safety analysis,and constructed building fire simulation methods and technical environment based on BIM.By studying the common data exchange IFC standard of BIM technology,a framework of building fire simulation and safety analysis based on BIM is established.The framework is based on IFC standard,including fire simulation,structural analysis and detailed design.This paper focuses on the expression,storage and transformation of fire simulation data and structural analysis data.The main part of the fire simulation is convertting geometry and materials of IFC building components into a fire model.There are two major descriptions of the shape of building elements in IFC standard.One is stretched body of rule component and the other is boundary expression of the irregular component.The stretched body are divided into several layers,each layer is converted to a fire model.Boundary expression body is composed of triangular patches and polygonal patches.This paper studied the conversion of these two kind of patches into a fire model and analyzed the factors that affect the conversion accuracy.A method of making the fire model more accurate is presented.Two methods are used for material conversion,one is direct conversion and the other is using the material library.Using the material library is a better choice.Finally,the fire simulation data formed of a set of attributes.These attributes are associated with the building element and they are stored in the element.The main part of the fire simulation is how the structure information were stored in IFC standard.First of all,three aspects are studied: relationship between building model and structure model;relationship between building component and structure component;the description of structural model and structural component information in IFC standard.On the basis of previous studies,an idea to convert the structure model to FEM model is proposed.This idea involved profile,material and connection.Finally,the fire simulation results are extracted from the IFC and the information is used to build the FEM model.The method above is applied to a shopping mall.The FEM model and the fire model was extracted from IFC file of the shopping mall.Finally,the simulation results are used in detailed design.