Application of tolerance management to civil systems

The negative impact of variability on civil systems projects is investigated in research in Lean Construction. However, geometric variability has received little focus. Geometric variations due to tolerances can have costly direct and indirect impacts in civil systems, which include architecture, engineering, and construction (AEC) projects. Nevertheless, AEC practitioners and researchers, overall, lack an understanding of how tolerances and tolerance problems propagate throughout a project. In contrast, investigation into manufacturing reveals more advanced techniques and strategies for tolerance management that have resulted in significant improvement in manufacturing efficiency and product quality. This research investigates the application of manufacturing tolerance management techniques and strategies to civil systems. The author looked at many industry practices and reports in-depth on three case studies. The first case investigates structural steel bolt connections on the seismic retrofit of a steel suspension bridge. The second looks at the interface between windows and cast-in-place concrete in a multi-story building. The third deals with the connection between steel roof girders and soldier piles within a slurry wall on a highway tunnel project. Through the application of tolerance mapping, tolerance analysis, vector modeling and tolerance standards to civil systems, the author demonstrates that manufacturing tolerance management techniques successfully predict potential tolerance problems within an existing design. The author further demonstrates that these techniques can direct generation of new designs, design alternatives, or tolerance reallocations that mitigate or prevent tolerance problems in civil systems. In addition, the author provides the requirements of a good tolerance specification. Finally, the author develops a novel AEC Tolerance Management Theory, which is based on identification of six specific tolerance failure modes and provides the blueprint for managing tolerances in civil systems.