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Kim, K.H.; Shim, K.T., and Shin, B.S., 2016. Morphological Change near the Artificial Reefs as a Beach Erosion Countermeasure. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 403-407. Coconut Creek (Florida), ISSN 0749-0208. At the Namhangjin Coast on the eastern coast of South Korea, there are five artificial reefs constructed as a form of countermeasure to prevent beach erosion. Since the construction, severe beach erosion has not occurred, and due to the presence of the artificial reefs various sedimentation effects have taken place. However, inside the opening gaps between the artificial reefs, the occurrences of return flow and severe scouring have been observed. In this field investigation the effects of one of the six artificial reefs, installed particularly for abalone, seaweed and fish farming, have been reviewed. Furthermore, the effects of the artificial reefs and their ensuing problems were investigated via three-dimensional movable-bed experiment. In the experiment, to improve the performance the artificial reefs, the impacts of raising the crown height and style of the reefs were examined. The numerical model has successfully explained the various implications of the three-dimensional experiment and the field investigation, and has confirmed the fact that there exists a shared agreement. [ABSTRACT FROM AUTHOR]

In this recent work, a ground penetrating radar (GPR) technique was proposed to evaluate the deteriorated depth of concrete bridge decks with asphalt overlays in the Korea expressway network. Air-coupled GPR was utilized in the measurement of the relative permittivity of concrete on bridge decks with asphalt overlays and the electromagnetic (EM) wave attenuation of the concrete cover of top reinforcing bars (rebars) in the pilot bridge in public service. In addition, 13 core samples were obtained from the bridge deck to carry out a detailed survey that includes visual inspection of the deterioration and measurement of chloride content with depth. The validity of the GPR technique was examined by comparing it with the results of the field investigation. Moreover, the correlation of the deteriorated depth with either the relative permittivity or EM wave attenuation was established. Results show that a GPR signal analysis method based on a dual-criteria (relative permittivity and EM wave attenuation) is more effective in analyzing the deterioration characteristics and evaluating the deteriorated depth of concrete bridge decks with asphalt overlay compared to the analysis method based on one of the two GPR properties. Results of the field test are considered to be significant wherein it establishes a relationship between the GPR property and deterioration characteristics of the bridge decks. Moreover, results show the practical applicability of the GPR technique in evaluating the deteriorated depth of the bridge decks with asphalt overlay. [ABSTRACT FROM AUTHOR]