Hurricane Protection Structure for London Avenue Outfall Canal, Lake Pontchartrain, New Orleans, Louisiana.

The 120-scale physical model investigation was conducted to give a three-dimensional analysis of the hydraulic performance of the unique vertical butterfly-gated structure, measure the torque on each gate shaft due to incoming and outgoing flows, and evaluate the effects of wave action on the gates. The model was also used to align the canal to provide a more uniform flow distribution through the structure and measure the water-surface differentials across the structure. Model tests indicated that the original design did not perform as intended therefore, a solution was obtained by modifying the geometry of the canal and gates by trial and error. The recommended crescent gate design performed satisfactorily for anticipated incoming and outgoing flows. Storm waves are measured along the reach of the canal from the lake to the structure to determine the maximum wave heights propagating in the canal. The model also indicated that the torque on each gate shaft decreased with waves superimposed during pumping operations and increased with waves superimposed during storm surges. The results of the torque measurements are presented in Appendix A to give design information for sizing the dampening device which operates as a shock absorber, the vertical shafts, operating machinery, and structural components.