Research On Consistency Problem Of IFC Data

The application of BIM(Building Information Modeling)technology is the inevitable result of the informationization development in the construction industry.The final goal of BIM technology is to achieve information sharing and exchange among multiple fields and phases.The uniform data stansards are the basis for the development of BIM.The IFC schema is the international standard which is used to describe the information in the whole life-cycle of the construction industry and also the basis to solve the core problems of the development of BIM technology.The practical application of IFC schema is impossible without the support of professional softwares,but mainstream BIM softwares do not give perfect support for the IFC schema.When IFC files are transmitted between different BIM softwares,the information is inconsistent.This situation restricts the practical application of IFC schema and also hinders the development of BIM technology.The main goal of this paper is to analyze the causes of ambiguity and errors of IFC data exchange between different softwares and propose feasible solutions to solve the problems of inconsistent data exchange.This research work has done a lot of output and input tests of IFC files using four kinds of model systems between three mainstream BIM softwares and summarized the reasons for IFC data exchange problems.This paper presents two ways to solve the problems caused by the IFC data inconsistency.One method is the verification of IFC data,the other one is the expansion of IFC entities in the layer field.The former can be used to verify the validity of IFC data and extract entities and attribute information according to the needs of users,which can solve the problem that professional softwares can not extract IFC model information completely.The later proposes to expand the entities in the layer field of IFC schema focusing on the phenomenon that the IFC schema is not perfect.The paper verifies the feasibility of the later method on the platform of SJTUBIM which is self-developed by Shanghai Jiao Tong University.