Experimental study of the short-term efficiency of different breakwater configurations on beach protection

Abstract

A campaign of experimental tests on a 2D movable-bed physical model, reproducing an Italian beach on the Adriatic Sea, has been performed in the wave flume of the "Laboratorio di Idraulica e Costruzioni Marittime" of the Università Politecnica delle Marche (Ancona, Italy), with the aim to assess the fundamental features of various breakwater configurations to be used in a beach-defence system typical of sandy, low-coastline beaches. Three emerged and three submerged configurations of rubble-mound detached breakwaters, for beach protection, placed at different distances from the shore, were tested, as well as a free beach configuration. The short-term hydrodynamic performances of the different configurations were assessed using as forcing some typical real-life intense sea-storm conditions. Wave transmission and beach protection efficiency under various intense wave conditions were obtained and related to some dimensionless parameters, amongst which a recently introduced one, χ , that combines both wave and breakwater properties. Transmission coefficients were found to be about 0.4 for emerged breakwaters and in the range 0.5-0.8 for submerged breakwaters. A net damping coefficient, defined as the wave height decay solely due to the effect of the breakwater, was measured as 0.2 for submerged breakwaters and 0.4 for the emerged ones. Further, submerged breakwaters induce an inshore mean water superelevation that increases with χ ,

Medium-term dynamics of a middle Adriatic barred beach

“…In fact, such predictions are associated with both the mean sea-level rise and the more frequent sea storms, occurring during both summer and winter. The understanding of the main physical processes driven by such changes is fundamental for (i) the modeling of the nearshore dynamics, including rapid morphological changes to the beach (Postacchini et al, 2016b), (ii) the correct prediction of coastal flooding (Villatoro et al, 2014), (iii) the proper design of protection solutions (Lorenzoni et al, 2016) and (iv) the correct analysis of future scenarios in the coastal area (see Benetazzo et al, 2012;Lionello et al, 2012).…”

Can ICZM Contribute to the Mitigation of Erosion and of Human Activities Threatening the Natural and Cultural Heritage of the Coastal Landscape of Calabria?

“…Specifically, underwater archaeological goods could be better protected using semi-submerged mattresses made of geo-textile materials filled with sands. Indeed, such mattresses can be easily placed on, or removed from, the seabed and around archaeological remains [40][41][42]. The transplantation of Posidonia oceanica (Linnaeus) Delile shoots [43,44], as well as the use of its seedlings [45], is a potential coastal restoration intervention that can be carried out in those coastal areas subject to higher human pressure, and in proximity of dead "matte" of Posidonia oceanica meadows.…”

A Study of Hydraulic Characteristics in Front of the Seawall under the Coexistence of Wave and Wind

“…최근 발생빈도와 규모가 증가하고 있는 고파랑은 일반적으 로 강풍을 동반하기 때문에 사석경사식의 구조물에서는 제체 의 경사면을 따라 높은 처오름과 대규모 월파가 발생된다 (Carrasco et al, 2018;Lorenzoni et al, 2016 (Franco et al, 1994;Bruce et al, **가톨릭관동대학교 토목공학과 강사(Lecturer, Civil Engineering, Catholic Kwandong University) **가톨릭관동대학교 토목공학과 교수(Corresponding author: Kyu-Han Kim,Professor,Civil Engineering,Catholic Kwandong University,24 Beomil-ro 579 beon-gil, Gangneung-si, Gangwon-do 25601, Korea, Tel: +82-33-643-3436, Fax: +82-33-647-3436, khkim@cku.ac.kr) 심규태 • 김규한 2018; Kerpen et al, 2019;Kim et al, 2019), 최근에는 방 재측면 뿐만 아니라 해역의 환경•이용면을 고려한 새로운 형 식의 호안의 개발 및 설계가 계획되고 있다 (Li et al, 2015;Kerpen et al, 2019). 대표적으로 월파를 제어하기 위해 직 립식 방파제에 월파저감시설을 설치한 후 그 효과를 유도함 과 동시에 호안전면에 소파블록을 병용하여 월파제어를 검토 한 사례가있으며 (Murakami et al, 1996), 방파제뿐만 아니라 호안 상단에 호안과 일체형으로 설치된 곡선 형상을 갖는 반 파형 구조형식에 대한 월파저감 효과를 검토한 연구가 있다 (Altomare et al, 2016;Pearson et al, 2004;Pullen et al, 2009).…”