The Second Penang Bridge currently under construction connects the mainland Malaysia to the Penang Island. The total length of the estimated 1.5 billion US Dollar bridge is 24 km, 17 km of which runs over the sea with a water height clearance of 30 m, making it the longest bridge in Malaysia and Southeast Asia.

The paper will address the seismic risk to this major new structure from large far field events, resulting in the decision to use isolators to reduce the seismic loads on the structure due to 2500 year return period seismic event. The choice was made to use High Damping Natural Rubber (HDNR) isolators for the seismic protection of the sea section as well as the land expressway part of the bridge. The paper will discuss the reason behind the choice of the Standards used in the design of the isolation system and the actions the bearings are required to meet. The creep and shrinkage of the 6 span modules of the sea section deck, each 330 meters long, posed a challenge to the design and installation of the isolation bearings. A design was evolved to meet this and other challenges and will be described in the context of the overall structure and the construction method.

A total number of 1352 HDNR bearings are required for the sea section. The land expressway section of the bridge requires 882 HDNR bearings. The deck for the sea section is pre-stressed box girder units supported by two bearings of the two types of bearings designed for this section. In contrast, the deck for the land expressway portion is cast in situ on precast inverted “T” section beams spanned between the piers. Six different types of bearings were designed for the land expressway. The bearings have been manufactured in Malaysia under the supervision and quality control of the Malaysian Rubber Board (MRB). All of the bearings were tested in the presence of the MRB research officers in accordance with the international standards in compression and shear at the manufacturer’s testing facility.

The design and prototyping of all bearing types have been completed and by the end of 2012 about 80% of the bearings were delivered to the site. The installation of the bearings on the piers of the sea and land expressway sections begun in August 2011 and July 2012 respectively. The bridge to be opened in September 2013 would be the longest structure in the world mounted on seismic isolators.

The paper will present the dynamic properties of the bearings under different conditions and also describe how the innovative mechanism for dealing with the shrinkage of the deck after installation has performed.