Spillway Rehabilitation: A Labyrinth Weir Design Tool

A design example is presented to illustrate the labyrinth weir hydraulic design and analysis method developed by the authors. This design method is based upon experimental results from physical models tested at the Utah Water Research Laboratory. It is valid for trapezoidal labyrinth weirs with sidewall angles from 6° to 35°, quarter-round and half-round crest shapes, and it includes various design parameters and hydraulic conditions that affect flow performance, including weir geometry, orientation (e.g., reservoir vs. channel), cycle configuration, cycle efficiency, tailwater submergence, local submergence, nappe aeration conditions, nappe vibration, nappe instability or flow surging, and artificial aeration (vents, nappe breakers). The validity of this method is established by comparing predicted results to data from previously published labyrinth weir studies. 15 pp. 15 references.