Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Civil and Environmental Engineering

Committee Chair(s)

Brian M. Crookston


Brian M. Crookston


Greg Paxson


Austin Ball


Evolving methods of dam construction and rehabilitation require unique and innovative spillways. Spillways provide passage for water impounded by a dam. Stepped chute spillways offer an efficient and economical solution for dam construction and rehabilitation. Labyrinth weirs, which allow high flow discharge within a compact footprint, are often an economical solution for the spillway crest at a chute entrance. Labyrinth weirs have recently been combined with stepped chutes in several locations. However, published literature is scarce for the flow properties and key design parameters of these combined structures.

This study researched the hydraulics downstream of a labyrinth crest for two stepped chutes and one smooth chute. The results of this study, which appear herein as Chapter 2 and Chapter 3, are in the form of two academic articles for consideration by hydraulic engineering journals. Results included visual flow patterns, air concentration profiles, velocity profiles, turbulence intensities, transverse and streamwise flow uniformity, and energy dissipation of the labyrinth weir and spillway structures.

The results showed stepped chutes with labyrinth crests achieve flow uniformity farther upstream than predicted by previous research, despite initial three-dimensional flow patterns. The rate of energy dissipation was low immediately downstream of the labyrinth weir but increased farther downstream as uniform flow was established. These findings provide improved design guidance for stepped chutes with labyrinth crests.