TR055: Representation and Reasoning for Integrated Structural Design

This research effort addresses the general framework required for integration of the activities that constitute structural engineering reasoning during the life cycle of a facility, specifically a high-rise commercial office building. As part of that framework, the global process by which buildings are conceived, design, built, and operated is defined in order to put the structural engineering activities in perspective and to identify the sources of interaction among the domains of design, construction, and facilities management. The reasoning that is performed in the structural engineering domain during the various phases is defined, and a system architecture that accommodates the multiple contexts created by the intersections of phases and domains is proposed.

The framework provides the motivation for using model-based reasoning for integrated structural design. The proposed approach incorporates iterative constraint formulation, propagation, and satisfaction, using first principles rather than heuristic rules. Decisions regarding alternative systems, components, or attributes are based on reducing the Cost/Value of the building as a whole.

Decomposing the structure description into form, function, and behavior objects facilitates both representation and reasoning. Based on the method of decomposition, a constraint classification system that facilitates both the coordination of the design and the integration constructibility issues is developed. The representation of the objects required to fully define form, function, and behavior at a typical floor is developed to demonstrate the potential efficiencies of the representation scheme.

The reasoning necessary to describe the structure function qualitatively in terms of load paths is examined in detail, and a vocabulary of functional elements and attributes capable of representing the structure function explicitly in the facility database is proposed. Qualitative structure behavior is examined, and the classical approximate techniques that are used to model the structure during the synthesis of lateral systems are addressed. Existing methods of representing the structure form are studied to determine the level and nature of the detail required to support construction and facility management activities - as well as design.