BIM for infrastructure: an efficient process to achieve 4D and 5D digital dimensions

The introduction of Building Information Modeling (BIM) approach in Civil Engineering practices allows an optimization of design through both an improved control of all the components of the project and an increased efficiency in the collaboration between all the professionals involved. In Italy, an increasing attention is being paid by scientists and professionals on the matter, especially due to the publication of the national law DM 560/2017, which will gradually rule the integration of the BIM-based procedures for contractors in major public tenders. The present paper aims to propose a methodology for implementing a dynamic model that permits to optimize time (4D) and cost (5D) efficiency in the different project phases. To achieve this goal the process relies on several authoring tools and 4D/5D modeling software, capable of enclosing the multiplicity of the project data in a unique and shared environment. This study focuses on the most effective methodology to maximize the interoperability between the various used codes. To this effect, a dynamic model involving an optimization-oriented approach for both the quantity surveying and the definition of the design management timeline is presented, which stand as two of the major issues concerning the evaluation criteria of a civil engineering project. Finally, it is important to underline that this bidirectional process allows for an advanced costs estimation of the project and an optimized timeline of the construction activities. Moreover, in case of unavoidable changes during the design phase, it permits to effectively reiterate the process with significant reduction on the overall computational times.