Process Improvements in Precast Concrete Construction Using Top Down Parametric 3d Computer Modeling

Ghang Lee

Ph.D. Candidate, College of Architecture, Georgia Institute of Technology, Atlanta, Georgia

Rafael Sacks, Ph.D.

Research Scientist, College of Architecture, Georgia Institute of Technology, Atlanta, Georgia

Also, Lecturer, Faculty of Civil and Environmental Engineering, Technion – Israel Institute of Technology, Haifa, Israel

Charles E. Eastman, Ph.D.

Professor and PhD Program Head, College of Architecture

Also, Professor, College of Computing, Georgia Institute of Technology, Atlanta, Georgia

Design professionals worldwide have applied the technology of computer-aided design and drafting (CAD) on a broad scale, primarily to increase the efficiency of manual design and drafting methods and to promote standards, rather than to improve the process itself. Even with improvements in the technology, however, errors in design and drafting remain common. Taking the 2-D CAD technology further, the application of three-dimensional integrated parametric modeling of precast buildings at the assembly and piece levels may enable producers to greatly reduce design errors, resulting in significant improvements in project quality, cost, and schedule. An examination of a number of case studies of precast/prestressed concrete projects has revealed that the common causes of construction problems are design, detailing, and drafting errors, a lack of coordination between different disciplines, and inadequate management of changes.

An analysis of the cases presented in this paper indicates that the application of 3-D top-down modeling and automated production of shop drawings holds the potential to eliminate most of the sources of error.

Although computer-aided drafting has become prevalent in all branches of the construction industry, a significant portion of construction dollars is still spent on correcting errors made in the design stage. Building parts that do not align correctly, spatial conflicts between components of different systems, and work that must be demolished because drawings were not updated to reflect design changes are among the common errors.

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