Yaquina, Oregon, North Jetty Stability Study

摘要

The Yaquina, Oregon, north jetty has been damaged and repaired many times. Armour design at the site is complicated by 10 m design waves that interact with tidal and longshore currents. In addition, a shore-parallel reef extending north from the north jetty constrains the longshore currents to jet out at the north jetty tip. Physical model studies have been conducted to design previous rehabilitations, but damage continues to erode the outer 120 m of the north jetty. A new physical model study, described herein, was conducted to design a repair. The study included incident waves, tidal currents in the channel, and longshore currents. Preliminary results showed that the more accurate physical model study, based on more detailed and extensive prototype measurements, illuminated both the failure mechanisms and the best repair alternative. It was shown that steady currents reduced stability substantially. Finally, location of the jetty tip repair away from the reef appeared to increase stability significantly.