Lyme Regis Lyme Regis No longer Slip-sliding No longer Slip-sliding
AwayAway
September 1, 2006September 1, 2006
IntroductionIntroduction
LocationLocation
EnglandEngland Southwest CoastSouthwest Coast DorsetDorset Jurassic Coast World Jurassic Coast World
Heritage SiteHeritage Site Exposed to severe Exposed to severe
winter stormswinter storms
West, 2006
Stormy WeatherStormy Weather
Undated, 1970’s stormSource: West, 2006
Calm WeatherCalm Weather
The Geology of Lyme RegisThe Geology of Lyme Regis
GreensandGreensand ClayClay ShaleShale Blue LiasBlue Lias
Steep slopeSteep slope
The Beginnings of a LandslipThe Beginnings of a Landslip
Charmouth Road Car Charmouth Road Car ParkPark
Asphalt is contributing Asphalt is contributing to landslipto landslip
Work underway to Work underway to improve drainage improve drainage systemsystem
The Black VennThe Black Venn
Between Lyme Regis Between Lyme Regis and Charmouthand Charmouth
Mostly Clay and Mostly Clay and Shales with BeefShales with Beef
Prone to landslidesProne to landslides Rich source of fossilsRich source of fossils
The Blue LiasThe Blue Lias
West of Lyme Regis at West of Lyme Regis at Monmouth BayMonmouth Bay
GreensandGreensand ClayClay LimestoneLimestone
LandslidesLandslides
1962 Langmoor 1962 Langmoor GardensGardens
Caused by Caused by construction activitiesconstruction activities
The area was re-The area was re-graded and Langmoor graded and Langmoor gardens were gardens were establishedestablished
The SpittlesThe Spittles
East of Lyme RegisEast of Lyme Regis The whole system was The whole system was
reactivated in 1986reactivated in 1986
Long-shore drift interruptedLong-shore drift interrupted
Beach buildupBeach buildup Monmouth beach Monmouth beach Increased protectionIncreased protection
Beach depletionBeach depletion Shingle supply Shingle supply
interruptedinterrupted This results in depletionThis results in depletion
The depleted beach(1960’s) and The depleted beach(1960’s) and breached seawall (1974)breached seawall (1974)
Coastal Defenses - The CobbCoastal Defenses - The Cobb
Coastal ReinforcementsCoastal Reinforcements
Beacon Rocks extended by 110 metersBeacon Rocks extended by 110 meters North wall rockery realignedNorth wall rockery realigned Added rock armor at Cobb GateAdded rock armor at Cobb Gate New jetties at Lister Gardens and Cobb New jetties at Lister Gardens and Cobb
GateGate Beach replenishmentsBeach replenishments Sand and shingle Sand and shingle
Raised beach level by 2 metersRaised beach level by 2 meters
Beacon RocksBeacon Rocks
Armor rocks:Armor rocks: 11,000 tonnes core rock, 2 - 5 tonnes each11,000 tonnes core rock, 2 - 5 tonnes each 26,500 tonnes armor, 9 - 18 tonnes each26,500 tonnes armor, 9 - 18 tonnes each Source: Norwegian graniteSource: Norwegian granite
Byproduct of granite counter top industryByproduct of granite counter top industry
Shingle (pebbles):Shingle (pebbles): 72,000 tonnes72,000 tonnes Source: Isle of WightSource: Isle of Wight
Sand:Sand: 37,000 tonnes37,000 tonnes Source: northern FranceSource: northern France
Precast concrete:Precast concrete: Source: UKSource: UK
Limestone facingLimestone facing Source: ChinaSource: China
Rock Armor at Cobb Gate JettyRock Armor at Cobb Gate Jetty
Finishing up at Cobb Gate JettyFinishing up at Cobb Gate Jetty
Reinforcements at Cobb GateReinforcements at Cobb Gate
Lyme Harbor beach restoredLyme Harbor beach restored
Work continues at Langmoor Work continues at Langmoor GardensGardens
Slope stabilizationSlope stabilization
Began in 2005, scheduled completion 2007Began in 2005, scheduled completion 2007 Major engineering effort involved Major engineering effort involved
considerations for seismic stabilityconsiderations for seismic stability Only small equipment allowed until slope Only small equipment allowed until slope
was sufficiently stabilizedwas sufficiently stabilized Gradual increase in machinery size based Gradual increase in machinery size based
on monitoringon monitoring
1,150 auger-cast piling1,150 auger-cast piling Drilled holes thru clay into bedrockDrilled holes thru clay into bedrock Filled with concrete and reinforcementFilled with concrete and reinforcement Act as dowels to hold slopeAct as dowels to hold slope
Soil nailsSoil nails Similar to piling but horizontalSimilar to piling but horizontal
2,300 meters drainage 2,300 meters drainage Counterforts - at baseCounterforts - at base Drilled drains -in hillDrilled drains -in hill French drains - below car parkFrench drains - below car park
ConclusionConclusion
Phase II construction is nearly completePhase II construction is nearly complete Coastal defensesCoastal defenses Slope stabilizationSlope stabilization Increased security for townIncreased security for town Increased income due to tourismIncreased income due to tourism Cost to maintain will be less than the cost of Cost to maintain will be less than the cost of
emergency repairsemergency repairs
Top Related