Submerged Geosynthetic Reef as Shore Protection Measure for Islands  

用于海岛护岸措施的浸没合成礁研究

作　　者：Vallam Sundar Sannasi Annamalaisamy Sannasiraj Sukanya Ramesh Babu Dipak Kumar Maiti 

机构地区：[1]Department of Ocean Engineering,Indian Institute of Technology Madras,Chennai 600036,India [2]West Bengal State Fisheries Development Corporation Limited,Kolkata 700091,India

出　　处：《Journal of Marine Science and Application》2022年第1期128-139,共12页船舶与海洋工程学报（英文版）

摘　　要：The Sagar Island,located north of the Bay of Bengal,intercepts the flow in the Hoogly estuary that comprises a network of several estuarine distributaries and creeks,which is considered to be one of the largest estuarine systems in the world.The Hooghly River experiences a tidal range in the order of about 4 m,due to which the tide-generated currents drive the sediments which are continuously set in motion.The temple,Kapil Muni(21°38'15.35"N,88°4'30.56"E)is located on the south-western side of Sagar Island,where an annual religious festival and rituals with about a million pilgrims is conducted.The pertinent erosion problem at a rate of about 5 m/year is prevalent at the site has considerably reduced the beach width,thereby,resulting in reduced space for religious as well as recreational activities along the coast.A novel cross-section for the proposed submerged reef using geosynthetic materials is designed considering the different sitespecific,environmental,and socio-economic conditions.The submerged reef can effectively be devised to redistribute the current circulation pattern and trap the sediment for beach restoration.The performance of such a structure depends on its geometrical and structural characteristics,the location of the reef(i.e.)the water depth at the toe,distance from the coastline,wave-structure interaction,sediment transport and local morpho dynamics.The aforesaid criteria were optimized using a numerical model which predicted the average residual velocity in the site to be in the order of about 1 m/s.Owing to logistical constraints geosynthetic materials had to be employed.The detailed design of such a system arrived through numerical modelling and field measurements are presented and discussed in this paper.

关 键 词：Island coastal erosion Submerged reef Tide dominant currents Sediment movement Geosynthetic materials 

分 类 号：U656.3[交通运输工程—港口、海岸及近海工程] P753[交通运输工程—船舶与海洋工程]