Author(s): Kuswandi; Radianta Triatmadja; Istiarto
Linked Author(s): Radianta Triatmadja
Keywords: Run-down; Tsunami; Velocity; Scour; Duals physics
Abstract: One of the reason that is relevant to the damage of buildings is tsunami scouring. In most cases, the scour formation around the buildings is due to the increasing velocity near the bottom of the structure. Tsunami may flow surrounding a building during run up and run down. This is different to that of river flows where the water move in the downstream direction. The other different is that the tsunami surge move significantly faster than that of river flow and hence creating a significant scour depth within a much shorter time. The research was aimed to observe the characteristic of flow velocity during tsunami run-up and run down as a prime variable affecting the scour depth surrounding a cylinder pile. The observation was conducted using a numerical model namely Dual SPHysics which is an open source software. A dam break model was used to simulate tsunami surge in a numerical flume of size 20.7 x 0.4 x 1 m. The water depth at the upstream part of the flume was 0.5 m whilst the water depth in the downstream part of the flume that represents the coastal area was 0.2 m. The slope of the sea bottom was 1:20. The two parts of the flume were separated by a quick opening gate. A cylinder model sized 0.2 m was located 6 m downstream of the gate. The distance between the simulated water particles was 4.5 mm and hence the total amount of the water particles used in the simulation was 9 million. The result showed that during run-up, the flow in front of the building slowed down but the flow on both sides of the building increased. The flow characteristic during rundown was almost the same but of different direction and speed. Based on the characteristic of the flow surrounding the cylinder pile, the scouring depth and pattern may be approximated
Year: 2016