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Harbour Area Treatment Scheme Stage 2AHarbour Area Treatment Scheme Stage 2AConstruction of Sewage Conveyance SystemConstruction of Sewage Conveyance System

from North Point to Stonecutters Islandfrom North Point to Stonecutters Island

Site Visit by AESSite Visit by AES22 March 2014

ContentContent

• Background of the Project• Background of the Project

• Tunnel Construction• Tunnel Construction

• Geotechnical Monitoring• Geotechnical Monitoring

• Stakeholders and Community• Stakeholders and Community

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Harbour Area Treatment Scheme - Stages 1 and 2AHarbour Area Treatment Scheme - Stages 1 and 2A

NN

StonecuttersStonecutters Island

Sai Ying PunSai Ying Pun

Sandy BayNorth Point

Sandy BayCentralCentral

Wan Chai EastHATS Stage 1 Catchment

Ab d

Wan Chai East

HATS Stage 2A CatchmentCyberport Aberdeen

Outfall System (Completed in 2000)Ap Lei ChauHATS Stage 1 Sewage Conveyance System

Ap Lei Chau

(Completed in December 2001)

Wah fu Proposed HATS Stage 2A Sewage Conveyance System (under construction)

Wah fuConveyance System (under construction)

33

Achievement of HATSAchievement of HATS

R t f l i Vi t i H b i 2004 t d i l l• Return of corals in Victoria Harbour since 2004, as reported in local

newspapernewspaper

• Re-open of 7 beaches in Tsuen Wan District – 4 were re-opened in• Re-open of 7 beaches in Tsuen Wan District – 4 were re-opened in

Jun 2011, 1 was re-opened in Sep 2013 and the remaining 2 will be p p g

re-opened in 2014re-opened in 2014

• Cross Harbour Race was resumed in 2011 at the east side of• Cross Harbour Race was resumed in 2011 at the east side of

Victoria Harbour

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HATS Stage 2A - Sewage Conveyance SystemHATS Stage 2A - Sewage Conveyance System

Ap Lei ChaiNorth Point p

AberdeenTunnel J Aberdeen

Tunnel K

S i Yi PSai Ying Pun

Tunnel L

Contract NoContract No.DC/2007/23DC/2007/23

LegendStonecutters Island

DC/2008/09g

Stonecutters IslandDC/2008/09

DC/2007/24DC/2007/24

DC/2007/23

55

Contract No DC/2007/23Contract No. DC/2007/23

Client Drainage Services Department (HKSAR)g p ( )

Engineer AECOM Asia Co. Ltd.Engineer AECOM Asia Co. Ltd.

Contractor Gammon Construction LtdContractor Gammon Construction Ltd.

Major Features Tunnel Length: 12kmMajor Features Tunnel Length: 12km

C t t S HKD $3 7 BilliContract Sum HKD $3.7 Billion

ContractContract C t

July 2009Commencement

July 2009

Anticipated Completion Main Works by end 2014Anticipated Completion Main Works by end 2014

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Sewage Conveyance System fromSewage Conveyance System from North Point to Stonecutters IslandNorth Point to Stonecutters Island

DS PS(JS)DS & PSDS & PSNorth Point

DS PS(JS)DS & PSDS & PSWan Chai East Central Sai Ying PunNorth Point Wan Chai East Central Sai Ying Pun

To Stonecutters Island

PS(JS)RS & PSLegend Sai Ying PunStonecutters Island

Soil Layerg

Rock LayerRock LayerDS Drop ShaftDS Drop Shaft

PS Production ShaftPS Production Shaft

JS J ti Sh ftJS Junction Shaft

RS Ri Sh ftRS Riser Shaft

77

Typical Sections of TunnelsTypical Sections of Tunnels

Twin Pipes Single Pipep(N h P i S i Yi P )

g p(S i Yi P SCISTW)(North Point to Sai Ying Pun) (Sai Ying Pun to SCISTW)

2( Approx. excavated size : 3.7x3.7 to 5.9x5.9 m2 )( pp )

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Key Considerations for Deep Sewage TunnelKey Considerations for Deep Sewage Tunnel

E tensi e tr ffi nd tilitiesJardine House

Extensive traffic and utilities (52 floor building)

diversion would be involveddiversion would be involved

I i d tSewageSewageT lT l160m160m Inconvenience caused to TunnelTunnel160m160m

publicpublic

• Tunnels underneath major urbanized areasj

• Cover to the tunnels > 30m of bedrock• Cover to the tunnels > 30m of bedrock

MTR MTR• Avoid affecting the foundation of existingAvoid affecting the foundation of existing buildings and facilities

SewageSewagebuildings and facilities

Sewage Sewage TunnelTunnel

• Avoid encroachment into private landsTunnelTunnel

• Geology• Geology

99

Hydraulic Design – Inverted Siphon SystemHydraulic Design – Inverted Siphon System

About 170mGround

G it S tGravity SystemPumping

H d

y y

L diff b t Head• Large difference between downstream water level Upstream

Downstreamand ground level

Downstreamg

• Higher pumping Head• Higher pumping Head

Hydraulic GradientGravity Method

Hydraulic Gradient

Inverted Siphon SystemGravity Method

Inverted Siphon SystemAbout 45mUpstream Ground Downstream• Small difference betweenSmall difference between

downstream water level anddownstream water level and ground levelground level

Hydraulic GradientPumping

Head• Lower pumping Head Hydraulic Gradient Headp p g• Less pumping cost• Less pumping cost

Inverted Siphon SystemInverted Siphon System

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T l C t tiTunnel Construction

1111

Tunnelling CycleTunnelling Cycle

After every 4 - 6 blasts y(typically)

Probe Ahead( yp y)

Measure Water InflowT S t

Measure Water InflowTemporary Support

P E tiScaling Mucking

Pre-Excavation G tiScaling, Mucking

and Geological MappingGrouting

and Geological Mapping

BlastingBlasting

(Drilling and Charging)( g g g)

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Pre Excavation GroutingPre-Excavation Grouting

Previous Grout HolesControl HolesControl Holes

Grout Holes

Tunnel Face

Blast

III III IV

Blast

Overlapp

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Pre Excavation GroutingPre-Excavation Grouting

High pressure grouting with micro-fine cement and colloidal silica has beenHigh pressure grouting with micro fine cement and colloidal silica has been applied to control groundwater inflow effectivelyapplied to control groundwater inflow effectively.

B f G ti f GBefore Grouting After Grouting

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Drilling Blast HolesDrilling Blast Holes

Drilling Blast Holes in Progress

Blast Holes Drilled

15

Blast Holes Drilled

15

Delivery of ExplosivesDelivery of Explosives

Kam ShanKam Shan Country

ParkPark

Kowloon ReservoirReservoir

Checking the Amount Kowloon Explosives Depot (KED)

gof Explosives at KED

16

p

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Collection and Delivery of ExplosivesCollection and Delivery of Explosives

Checking the Amount of ExplosivesChecking the Amount of Explosives at Blasting SiteDelivery of Explosives at Blasting SiteDelivery of Explosives

Cartridge ExplosiveCartridge Explosive

D t tDetonators

Detonating Bulk Emulsion Primer17

gCords

Bulk Emulsion Pump

Primer17Pump

Charging ExplosivesCharging Explosives

Charging Explosives Completed

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Warning and MonitoringWarning and Monitoring

Display Traffic Warning Vib ti d Ai ODisplay Traffic Warning Sign Board

Vibration and Air Overpressure M it i D i Bl tiSign Board Monitoring During Blasting

G i d W i R d FlGonging and Waving Red Flag 5 i B f Bl ti

19

5 mins Before Blasting19

Condition After BlastingCondition After Blasting

Cl N i E lClose Noise Enclosure

After BlastingAfter Blasting

Initiate Blasting

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Spoil RemovalSpoil Removal

H l dTunnel Locomotive Haggloader

Shuttlecar Mucking System2121

Temporary SupportTemporary Support

Rock DowelsGeological Mapping Rock Dowels

Shotcrete

ShotcretingShotcreting

Steel Ribs

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Tunnel Lining ConstructionTunnel Lining Construction

2323

G t h i l M it iGeotechnical Monitoringg

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Geotechnical MonitoringGeotechnical Monitoring

Piezometer

2525

Geotechnical MonitoringGeotechnical Monitoring

Ground Settlement Marker Structural Settlement Marker

Tell-tale2626

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GEOMON SystemGEOMON System

• Alert levelAlert level• Action level• Action level• Alarm levelAlarm level

Installed (No )Installed (No.)

G d S ttl t M k 517Ground Settlement Marker 517

Structural Settlement Marker 489Structural Settlement Marker 489

Piezometer 129Piezometer 129

Tell-tale 13

2727

St k h ld d C itStakeholders and Communityy

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Meetings with StakeholdersMeetings with Stakeholders

• District Councils• District Councils• SPCA• SPCA

C H b T l• Cross Harbour Tunnel• MTRC• Customs Marine Base • FSD Diving BaseFSD Diving Base

2929

School Talks and Activities to Introduce HATSSchool Talks and Activities to Introduce HATS

School Talks / Interview by the Students• School Talks / Interview by the StudentsD i C titi• Drawing Competitions

• Dragon Boat Raceg

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Charity / Community Caring EventsCharity / Community Caring Events

• Walk for Millions• Walk for Millions• Coastal Cleanup• Coastal Cleanup

Vi it t th Eld l C t• Visits to the Elderly Centres• Blood Donation Day• Pizza Making with Childreng

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Communication ChannelsCommunication Channels

7901 811124 ho r Hotlines 7901 8111• 24-hour Hotlines

Q t l N l tt• Quarterly Newslettersy

• HATS Project WebsiteHATS Project Website

http:/www dsd gov hk/http:/www.dsd.gov.hk/

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Thank You!Thank You!

Q & AQ & A