““Any object, wholly or Any object, wholly or partly immersed in a partly immersed in a fluid, is buoyed up by a fluid, is buoyed up by a force equal to the weight force equal to the weight of the fluid displaced by of the fluid displaced by the object.”the object.”
Archimedes PrincipleArchimedes Principle
Submitted BySubmitted BySashirekha JenaSashirekha Jena
Department Of Civil EngineeringDepartment Of Civil Engineering8th semester, Hi-tech institute of 8th semester, Hi-tech institute of
technologytechnologyRegd. no.0901300059Regd. no.0901300059
Introduction to VLFSIntroduction to VLFS
What’s VLFS?What’s VLFS?
Very Large Floating Structures, Very Large Floating Structures, constructed to createconstructed to create
Floating AirportsFloating Airports BridgesBridges Piers, Docks, Storages Piers, Docks, Storages
Wind/Solar power plantsWind/Solar power plants Industrial spaceIndustrial space Entertainment facilitiesEntertainment facilities Recreational parksRecreational parks Space vehicle launchingSpace vehicle launching Habitations (Futuristic)Habitations (Futuristic)
Floating Airport
prototype, The mega
float, Tokyo Bay, Japan
Floating Nuclear
power plant, Russia
General ClassificationsGeneral Classifications Pontoon TypePontoon Type
Simple flat boxedSimple flat boxedHigh stabilityHigh stabilityEasy maintenance & Easy maintenance & repairrepairLow costLow costMore reflexive than More reflexive than semi submersiblesemi submersible
Semi Submersible TypeSemi Submersible TypeGenerally suitable for Generally suitable for buildingsbuildings
Floating pontoon dock,
China
Basic ConceptsBasic Concepts
Based on Archimedes’ Based on Archimedes’ principleprinciple
Geometrical assumptionsGeometrical assumptions
Small amplitudeSmall amplitudeFinite, infinite & shallow Finite, infinite & shallow water depth caseswater depth casesFluid split into 2 regions-Fluid split into 2 regions-open water & plate regionopen water & plate regionIncident of surface water Incident of surface water on floating flexible plateon floating flexible plate
Archimedes’ Principle and
buoyancy.
Main ComponentsMain Components
BreakwaterBreakwater- A barrier that protects a shore from the full impact of - A barrier that protects a shore from the full impact of waves. waves.
LandLand- The solid ground of the earth. - The solid ground of the earth. Sea BedSea Bed- The floor of the sea or the ocean. - The floor of the sea or the ocean. Access Bridge/ShipsAccess Bridge/Ships- Entering/exiting medium- Entering/exiting medium SuperstructureSuperstructure-- Part of a structure above the foundation Part of a structure above the foundation Mega-floatMega-float- Gigantic floating structure.- Gigantic floating structure. MooringMooring facilityfacility- Any device that’s fixed in navigable water to - Any device that’s fixed in navigable water to
which a which a vessel can be made fast including vessel can be made fast including buoys, chains, ropes, buoys, chains, ropes, piles piles etc. etc.
Analysis of VLFSAnalysis of VLFS structure should provide a very large surface area.
constructed by joining numbers of floating units together.
must obey safety & strength requirements, operating conditions, etc.
Steel, concrete (prestressed or reinforced hybrid) or steel-concrete composite materials may be used.
floating structures shall be moored at the same site for a long time.
Design AspectsDesign Aspects
Design LoadsDesign LoadsDead load, hydrostatic pressure (including buoyancy), live Dead load, hydrostatic pressure (including buoyancy), live load, wind load, seismic loads, effects of water current and load, wind load, seismic loads, effects of water current and tidal changes, effects of pressures on mooring systems tidal changes, effects of pressures on mooring systems (dolphins) etc.(dolphins) etc.
Buoyancy, waves, current & windBuoyancy, waves, current & wind
Analysis of hydroelasticity.Analysis of hydroelasticity.
Dimensions, Depth of sea, wave frequency & Dimensions, Depth of sea, wave frequency & height, amplitude of incident wave for vertical height, amplitude of incident wave for vertical deflections etc.deflections etc.
AdvantagesAdvantages DisadvantagesDisadvantages
Fast to constructFast to construct Easily relocated, expanded or Easily relocated, expanded or
removedremoved Cost effective when water Cost effective when water
depth is largedepth is large Construction is not affected by Construction is not affected by
depth of seabed and wavedepth of seabed and wave Position of VLFS is constant Position of VLFS is constant
with respect to water surface- with respect to water surface- Hence used for airports, piers Hence used for airports, piers etcetc
Protected from seismic Protected from seismic shocks ,since energy shocks ,since energy dissipated by seadissipated by sea
Environment friendlyEnvironment friendly Structures overcome soil Structures overcome soil
erosion.erosion.
Mat –like VLFS only Mat –like VLFS only suitable in calm water suitable in calm water associated with naturally associated with naturally sheltered coastal formation sheltered coastal formation (solution-Use of mooring (solution-Use of mooring system)system)
Might not be sufficient Might not be sufficient stability for airport control stability for airport control system (solution-keeping system (solution-keeping these systems on a shore)these systems on a shore)
Low security (Bombing, Low security (Bombing, Terrorist attacks etc)Terrorist attacks etc)
Timeline…Timeline…
Present
Past
Future
Future AspectsFuture Aspects
Building floating citiesBuilding floating cities
Marine hotelsMarine hotels
Marine Marine accommodationsaccommodations
HabitationsHabitations
Advanced Oil factoriesAdvanced Oil factories