A STUDY OF PLANAR EVALUATION METHODS FOR WAVE DISSIPATING BLOCKS IN AIR AND IN WATER USING POINT CLOUD MEASUREMENTS

Abstract

 In Japan, which has a four-surface ocean ring, many ports and harbors are constructed with wave dissipating blocks to reduce wave reflection and wave overtopping. However, it is difficult to quantitatively determine the current shape of wave dissipating blocks by conventional measurement methods such as visual inspection because of the danger of activities directly above the blocks. Therefore, studies have been conducted using non-contact measurement methods, such as using point cloud data acquired by UAV surveying to evaluate the tops of wave dissipating blocks. However, there are only a few cases of application to slopes due to their characteristics of being continuous in air and water. Therefore, in this study, an evaluation method for slopes, including underwater areas of wave dissipating blocks, was investigated using point cloud data acquired by UAV surveying. As a result, it was shown that an planar evaluation using the highest value is useful for both the slope and the top edge, and it is expected to be utilized as a method to grasp the current status of wave dissipating blocks and to quickly grasp the situation at the time of damage.