Protecting Riverbank's Environment Towards Scour with Combined Reinforcement of Gabion and Tetrapod: A Laboratory Model Study

Abstract

The purpose of combined reinforcement installation is to direct the water flow and to reduce the scour process in order to protect the riverbank. The study was conducted by employing a laboratory model using a trapezoidal flume/channel with dimensions of 0.8 m width and 0.5 m height. The length of river bend model was 5 m. Observation was made with a constant flow rate of 7.07 liters/second. Tetrapod and gabion were installed at the angle of 45° and a distance of 51 cm. The running duration of installation variation was 180 minutes each. The results of the test showed that the river model with tetrapod-gabion-tetrapod reinforcement experienced an average scour of 4.16 cm for the beginning, 1.08 cm for the middle and 3.3 cm for the end. The gabion-tetrapod-gabion reinforcement can be considered as more effective reinforcement combination to reduce scour with an average scour of 4.03 cm in the beginning of the channel, 2.64 cm in the middle of the channel and 1.97 in the end of the channel.