design of port infrastructure for extreme events, by alan betts

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By Alan BettsIE Aust NSW Maritime Panel / PIANC

Half Day Seminar15/08/2011


• Introduction• Extreme Events

• Seismic• Tsunami• Waves • Storms - (Cyclones /

Typhoons / Hurricanes)• Sea Level Rise• Flooding

• Risk-based approach


• Presentation covers descriptions of how some extreme events have affected port infrastructure. It is not exhaustive.

• Describes the response provided to some events, both prior to & post event.

• Does not provide general design guidance for extreme events as each circumstance is different.

• The presentation is intended to provide a basis for further discussion. A vessel aground at Port of Busan, 2003


• Australian and NZ Standards and guidelines (AS/NZS1170, AS4997)

• British and European Standards (BS6349)/Eurocode

• DIN 4149 (German)• Hong Kong Port Manual• Japanese Standards• American Standards• PIANC - Seismic design

guidelines for port structuresMarCom report of WG 34 –2001

Design Considerations:• Structural Ductility• Soil Conditions• Response of Adjacent Structures • Structural Importance Factors• Stability of reclamation and

revetments• Services integrityAustralia - Newcastle earthquake, 1989, magnitude 5.6• Port Botany Container Terminal

Expansion Tsunamis - major seismic extreme events - covered later in presentation


Major caisson quay wall rotation at RoRo berth

Seawall rotation – preserved!


Aerial photo of port with reclamation works


Cashin Quay earthquake repair works

Reclamation works


• Magnitude and effect directly related to earthquake activity.

• Need specialist investigation to consider effects

• Design for tsunami may adopt a risk-based approach

• Tsunami early warning systems minimise adverse effects

• Devastating effects of the Indian Ocean Tsunami 2004.


• Sri Lanka• Magnitude 9 earthquake

off coast of Sumatra• Death toll 22,000• Top image 1 hour after the

wave hit showing water flowing back into the sea, turbulence off-shore

• Bottom image 1 January 2004 showing normal conditions


• Australian and NZ Standards and Guidelines (AS/NZS1170, AS4997)

• British and European Standards (BS6349)/Eurocode

• Hong Kong Port Manual• Japanese Standards• American Standards

Design Considerations:• Wave characteristics: height,

period, length• Recurrence interval• Lateral & uplift loads• Physical dimensions and nature

of structure (quay walls, revetments, breakwaters)

• Overtopping, run up of sloping revetments

• Combination with storm surge and tidal elevations

• Seiche effects


AS4997


One Example - Hong Kong Port Manual• 1 in 100 year wave with a 1

in 10 year water level• 1 in 10 year wave with a 1 in

100 year water level• 1 in 50 year wave with a 1 in

50 year water level• 1 in 100 year wave and

mean lower low water level

Coffs Harbour 1999


• Detailed Design and Site Support to Marine EPC• 650m of Caisson Breakwater• 70m x 40m x 25m Caissons Design of the Year Award


A typical inverted T-Shape was considered at tender stage, but replaced with an L-Shape during detailed design.


• Some ports and harbours are susceptible to seiche effects depending on their: shape, size and depth (resonance effects)

• These are non-tidal fluctuations in sea level are often caused during low depressions when the ocean interacts with coastal geomorphology and port infrastructure

• Some observed seiche effects have caused sea water variations up to 3 metres above predicted levels

• Needs particular investigation by specialist coastal engineers• Exposed ocean ports particularly susceptible (Napier, Taranaki) • May require breakwater reconfiguration and/or vessel

departure and/or mooring systems


Global average sea level rise projections range from 180mm to 600mm by 2099

Source: IPCC 4th

Assessment Report, 2007

(Does not include subsidence)


AS4997 – Guidelines for the Design of Maritime Structures prediction for sea level rise• 25 years – 0.1m• 50 years – 0.2m• 100 years – 0.4mSea level rise provided for by 2100 in various state coastal plans :• NSW – 0.9m • QLD – 0.8m• NT – 0.6m• WA – 1.0m• SA – 0.9mHeight of port and harbour structures needs to be carefully determined considering combination of adverse natural environmental effects: sea level rise, wind and wave effects


• Mean sea-level rise accelerating

• Tidal patterns could be influenced

• Increased storminesso Storm surges may

increase in height

• Increase in wind speeds

• Wave heights may change

Waves overtopping quay wall, Pakistan (photo: National Institute of Oceanography)

Waves overtopping Frankston Pier, Melbourne(photo: Friend of the Earth Melbourne Website)


Where breakwaters enclose and protect port infrastructure, overtopping of breakwaters would cause:

• Increased wave agitation in port basin (downtime for vessels)• Increased storminess would cause increased vessel movement• Increased vessel downtime can have severe impacts when

operating to fixed schedules


• Vessel elevation relative to wharf

• Significant overtopping causing flooding

• Likely to exceed land-based storm water drainage capacity

• Disruption to operationso Impacts at container terminals

where area behind wharf used for container storage

o Costs of damage to goods, plus future insurance costs

• Regular flooding could affect viability of port operation


Hong Kong Ports Manual provides the following guidance:

• Normal Wind-Loading: 1.2kPa compared with extreme loading of 3.0kPa during cyclones

• For wind gusts more than 44m/s the cyclone warning system is activated.

• Highest expected wind gust is 70m/s. This is the maximum gust expected to occur with a return period of 50 years in Hong Kong.


• Most maritime and building codes provide average (30 s) and gust (3 s) wind speeds

• Often based on historical data• NSW coast frequently

experiences east coast low depressions e.g. Pasha Bulker storm and Sydney to Hobart

• Northern half of Australia particularly susceptible to cyclones


Cyclone Jacob off Port Hedland 10 March 2007 (wind speed 140kph)(photo: NASA)

Panamax Coal Vessel (Pasha Bulker)

Aground on Nobbys Beach, Newcastle, after failing to hold anchorage in June 2007


Maximum Category: 5Maximum sustained wind speed: 205 km/hr Maximum wind gust:285 km/hr

Port Hinchinbrook Marina at Cardwell

Port of Townsville


• Need to investigate and understand the effect of naturally occurring extreme events - as provided for in current design standards and guidelines.

• Also need to consider provision for extreme events. • Consider an Asset Management approach – e.g. Lyttleton • Can damage be mitigated, or if sustained can the

infrastructure be economically reconstructed or replaced?• Should a risk based approach be adopted (frequency,

magnitude and probability of occurrence) related to consequences of property and infrastructure damage or loss of life?


• Neil McLennan – Engineering Manager Lyttleton Port of Christchurch

• Dick Carter – Former engineering manager at Port of Wellington and Nelson

• Ian Muir – URS/ Scott Wilson Asia Pacific Maritime Manager – Hong Kong

• Martin Mannion – URS/ Scott Wilson global head of Ports• Randy Mason – Maritime manager URS/Scott Wilson

USA• Sydney colleagues : Heli Lahteela, Kenan Aldemir and

Andrian Juric, who helped compile this presentation

design of port infrastructure for extreme events, by alan betts

Documents

nz standards

port of busan

port infrastructure

effects design

guidelines asnzs1170

earthquake activity

as4997 british

indian ocean tsunami