Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 EXPANSION JOINTS FOR EVER LONGER, LIGHTER BRIDGES Thomas Spuler Mageba SA 680

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 As engineers improve their methods, the achievable spans of bridges continually increase … … while using less materials in our effort to make what we do sustainable … … and stretching skywards to make this possible TallerLongerLighter,,

Taller, Longer, Lighter IABSE–IASS Symposium, London, September expand and contract -move due to wind / traffic / seismic forces etc -adjust to changes such as settlements  demands increase on expansion joints which enable decks to:

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Where movements of 300mm or less are required, simple expansion joints such as cantilever finger joints may suffice …

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 … but large bridges require more complex joints

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 To be considered: increased secondary, short-term movements due to wind, traffic and short-term temperature changes  Lifetime movements increase greatly - perhaps up to several hundred kilometres … for example, as the sun goes behind a cloud

Taller, Longer, Lighter IABSE–IASS Symposium, London, September ,000 vehicles per day for 40 years  approx. 200 million axle loads during life of expansion joints! And all this with increasing traffic!  need for ongoing development of technology

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Examples of expansion joint technology which addresses these challenges: Case study 1: Incheon Bridge, South Korea - Modular joints Case study 2: Audubon Bridge, USA - Sliding finger joints

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Case Study 1 Incheon Bridge, South Korea - Modular expansion joints

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 The modular expansion joints used offer great flexibility and can allow exceptional deck movements

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 The joints, shown here during shipping from Europe to South Korea, each weighed 42 tonnes

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Special features of the joints of the Incheon Bridge 1)Special sliding material 2)Elastic control system 3)Extra-durable key components 4)Anti-skid protection 5)Automated structural health monitoring

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Low friction characteristics friction level is approximately 5 times lower than that of PTFE Excellent abrasion resistance 20 times more durable than PTFE, tested to > 60km Higher admissible contact pressure Successfully passed an extreme pressure test of 220 N/mm 2 Low friction characteristics friction level is approximately 5 times lower than that of PTFE Excellent abrasion resistance 20 times more durable than PTFE, tested to > 60km Higher admissible contact pressure Successfully passed an extreme pressure test of 220 N/mm 2 1)Special sliding material ROBO ® SLIDE

Taller, Longer, Lighter IABSE–IASS Symposium, London, September )Elastic control system Regulating gap widths Preventing constraint forces Distributing loads to adjacent beams Transferring horizontal loads Countering rotations Damping dynamic loads Limitation bands ensure a defined maximum gap width Regulating gap widths Preventing constraint forces Distributing loads to adjacent beams Transferring horizontal loads Countering rotations Damping dynamic loads Limitation bands ensure a defined maximum gap width

Taller, Longer, Lighter IABSE–IASS Symposium, London, September )Extra-durable key components – proven by testing at - 20°C - including seismic testing in accordance with CALTRANS specifications

Taller, Longer, Lighter IABSE–IASS Symposium, London, September )Anti-skid protection, e.g. ROBO ® GRIP High friction level  increased traffic safety in all weather conditions Proven technology under comparable conditions (high loads, severe environment, e.g. sun, salt) Durable product thanks to multi- layer system (total 5 layers) Based on technology developed for aircraft carriers of the British Royal Navy High friction level  increased traffic safety in all weather conditions Proven technology under comparable conditions (high loads, severe environment, e.g. sun, salt) Durable product thanks to multi- layer system (total 5 layers) Based on technology developed for aircraft carriers of the British Royal Navy

Taller, Longer, Lighter IABSE–IASS Symposium, London, September )Automated structural health monitoring Permanent real-time information on bridge deck and joint movements Increased safety - early damage recognition Critical event alarms by SMS and Lower maintenance costs Permanent real-time information on bridge deck and joint movements Increased safety - early damage recognition Critical event alarms by SMS and Lower maintenance costs

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 These features help ensure that the joints of the Incheon Bridge will perform well for many years

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Further optional feature: Fuse-Box - allows joint to break out of deck in controlled manner during earthquake

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Fuse-Box protects the 17-gap joints of the Golden Ears Bridge in British Columbia

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Case Study 2 Audubon Bridge, USA - Sliding finger expansion joints When opened in May 2011 with main span of approx. 475m, became longest cable stayed bridge in Western Hemisphere

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Joint type for the ends of the main span For largest movements of 1,240mm, sliding finger joints were selected

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Developed from simpler cantilever finger joint, with following key differences: The sliding finger joint Tips of fingers of sliding finger joint receive sliding support from structure below Finger plates pre-tensioned downwards by springs

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Joint (half open) is approx. 3m wide and 2m deep – exceptional dimensions for a finger joint ~ 2m ~ 3m

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Depth of drainage channel due to 8% slope  challenges for transportation and assembly and anchoring needed to prevent vibrations Very large cover plates for cyclists Some of the challenges Unprecedented movement needs of 1,240mm for this type of joint  great precision required Some of the challenges:

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Due to great precision required, test finger plates produced to refine methodology

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Trial assembly of each joint also conducted, before application of corrosion protection

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Joints then disassembled to receive corrosion protection, and then re-assembled

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Special frames designed to ensure safe lifting, carriage, and adjustment and installation on site

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Drainage channels: Due to size, connected to joint on site, and anchored to bridge deck

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Lifting into position of a fully assembled expansion joint

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Lifting into position of second expansion joint at same location

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Following positioning of both joints at this location

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Completion in 2011 showed that even movements > 1m can now be facilitated by this type of joint

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Issues such as total movement during joint’s life must be assessed  e.g. sliding material can be considered -choice of materials (e.g. RoboSlide) -allow for maintenance and replacement Importance of early consideration of expansion joint needs Early consideration of expansion joint needs can avoid changes to designs, or even to structure on site and bridge can be designed with correct block-outs and bridge gap

Taller, Longer, Lighter IABSE–IASS Symposium, London, September 2011 Conclusions – a small but important detail in the construction of ever longer, lighter bridges require carefully selected and detailed key components such as expansion joints while also striving for greater cost-effectiveness and sustainability designed and built by a construction industry that continues to push the boundaries of span and performance Exceptional bridge structures,