Information theory-based approach for constructability assessment in truss structural systems

Abstract

Abstract The importance of constructability is often understated in the design phase of a construction project. Issues regarding constructability often do not receive sufficient attention until it is too late for design changes. This paper proposes a quantitative measure of truss structural system design that can be used as an index of constructability in the aspect of standardization and repetition elements at early design stages. Construction can be regarded as a co-operative undertaking among architects, who specify the form of a building, and builders, who implement construction tasks. The designed form alone does not provide enough information to specify feasible processes for actual building. Sufficient fabrication information is needed so that fabricators can be completely certain concerning how to actually build the form. The goal of this study is to establish a model for estimating the amount of information needed for construction based on Shannon's information theory. This amount of information is based on uncertainty concerning assembly construction in the topological graph of the designed form, and the knowledge base shared by the designer and the builder in a design-build communication model. In this paper, the entropy of uncertainty is shown as being quantified as an index of constructability assessment for the attributes of standardization and repetition. Markov chain, Monte Carlo method and symmetry-group theories are also used in our model to analyze different levels of assembly. The scope of this research is currently focused on analyzing the constructability of truss structure systems. The assessment of constructability is demonstrated for six different types of truss structural systems. The five alternative designs are assessed for a schoolhouse project in Cambodia requiring easy construction, identified by our theoretical model. The results show that our methodology can help architects to design easily constructed truss structural systems and explore important design principles for improving constructability. The limitations and future works are discussed in the final two sections.