Seawall – Shankarpur, India: Cross Section Can combine with use of conventional construction material for durability/armor.Įxamples of Use of Geosynthetics in Coastal Protection Gabion Armor Layer.Geosynthetic Materials present a possible costeffective alternative to conventional concrete/rock/rubble-mound structures.▫ MPASRs focus and reduce wave energy and provide recreational and ecological benefits. ▫ Submerged structure reduces wave energy shoreward of the structure. ▫ Where complete wave protection is not required nor necessary, can use submerged breakwaters. ▫ Type S: sloping breakwater ▫ Type V: vertical breakwater ▫ Type C: composite breakwater (combination of sloping & vertical) Harbors typically formed/protected by breakwaters ▫ ▫ ▫ ▫ ▫ ▫įormation of artificial harbors Protect an area inside against waves Reduce dredging at harbor entrance Serve as quay facility Guide currents Provide tranquility conditions inside harbor.Reef BallTM Units as Submerged BreakwaterĬonditions 3 years after Installation (Harris, 2006)Ĭoastal Protection, Surfing and Ecological Enhancement Reef BallTM Units as Submerged Breakwater, Grand Dominicus, Dominican Republic Period of observation too short to determine long term durability of tubes.No damage to materials due to pumping pressure or installation.Upon stabilization, a vegetative dune should be implemented to act as natural defense.No change was observed in natural currents seaward of tubes.Sand accumulation without interrupting littoral drift.Geotextile tubes initiate wave breaking farther from shore, dissipating energy transmitted shoreward.Yucatan Project Results/Conclusions Shoreline Response Sand Accretion After Tube Installation ResultsĬonditions shortly after installation (Alvarez 2008) Slurry pumps with 10-30% solids at 1000 gpm.Initial Conditions on Yucatan Coast Progreso Beach timber groinsĬonstruction – Filling of Geotextile Tubes

Project included: ▫ Elimination of structures perpendicular to shore to restore natural longshore sediment transport ▫ Beach nourishment from inland material banks ▫ Sediment bypass techniques at harbors along coast ▫ Reducing hydraulic load on specific sections of coastline to stabilize longshore sediment transport.Description: ▫ 4 km of geotextile tubes as submerged breakwaters ▫ Goal: restore natural coastal dynamic processes and provide a stabilized beach profile.Yucatan Peninsula Beach Restoration, MEXICO (ASR Marine Consulting and Research 2002) Dependent on local coastal dynamics, this can assist in stabilizing the coastline. Wave Refraction: MPASR causes wave refraction around the reef, focusing wave energy in a different direction.Hi = incident wave height seaward of structure. Ht= transmitted wave height shoreward of structure MPASRs as Coastal Protection Wave Transmission: MPASRs can reduce wave energy transmitted to shoreline. ▫ Surfing enhancement: can provide surfable breaking waves where none exist ▫ Diving/Snorkeling: can provide site for recreational diving and snorkeling ▫ Coral can be transplanted to initiate/accelerate coral growth ▫ Can provide environment for coral growth and habitat fish and other marine species. ▫ Can help restore natural beach dynamics by preventing erosion ▫ Can reduce wave energy transmitted to harbor entrances Coastline Protection or Harbor Protection.Multi-Purpose Artificial Submerged Reefs (MPASRs) Specifically designed artificial reef which can provide: Rocks Shells Trees Concrete Debris Ships Car bodies Designed concrete modules Geosynthetic Materials MPASR Concept for Kahului Harbor, Maui ▫ Situation ▫ Proposed Solutionīackground First documented artificial reefs in U.S.įirst specifically designed artificial reefs in U.S.Ĭreate Marine Habitat Enhance Fishing Recreational Diving Sites Surfing Enhancement Coastal ProtectionĪrtificial reefs in Hawaii– concrete/tire modulesĪrtificial reefs in Hawaii – concrete Zmodules.Multi-Purpose Artificial Submerged Reefs (MPASRs) ▫ Coastline Protection ▫ Harbor Protection.Harbor Protection through Construction of Artificial Submerged ReefsĪmarjit Singh, Vallam Sundar, Enrique Alvarez, Roberto Porro, Michael Foley

Submerge breakwater geotube