Author(s): Takaaki Abe; Hiroshi Yokoyama; Hiroya Ogushi; Yasuhiro Yoshikawa
Linked Author(s): Hiroshi Yokoyama
Keywords: River Ice; Ice-Structure Interaction
Abstract: This paper presents an investigation on the characteristics of ice floe movement around concrete structures located on estuarine regions. In cold snowy regions such as Hokkaido, Japan, ice is formed on the river surface and it is broken into pieces due to the increase in flow discharge during snowmelt season. As a result, bank protection made from concrete can be damaged by collisions between them and ice floes. In order to clarify the mechanism of such abrasion process, field observation of ice floe movement during winter season is conducted in the Abashiri River, Hokkaido, Japan. A set of pressure scale sheet is placed on the surface of riverbank structures and a video camera is installed above the targeted section of the river. A series of observation clarified that the measured averaged pressure caused by the ice floe contact varies from 10 to 50 MPa and has a maximum value around 300MPa. An image analysis technique is applied to reproduce the ice floe movement in the video image and the change in momentum of it is measured. Then a practical computational model for predicting interactions between ice floe and river structures is developed for further investigations. The method we use is the Moving Particle Simulation (MPS) method, which can be applied to structural analysis involving material fracture. The simulated results show that the model can reproduce the floe movement around river structures before and after the collision. In addition, the observed pressure wave inside the structure material is a trigger of collision-generated pressure on the structure surface. With the long-term field observation and complementary numerical techniques, this study succeeded in investigating the interactions between ice and riverine structures in the real field.
Year: 2022