manaswini VLFS

““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