The San Mateo - Hayward Bridge (SMHB) orthotropic steel spans were built in 1967 at a cost of $70M. It carries an average of 81,000 vehicles per day in both directions. The high rise portion of the SMHB has 3 lanes in each direction with no shoulders. The existing trestle or flat portion of the SMHB has 2 lanes in each direction with no shoulders. The total length of the bridge is 7 miles. The high rise portion is 1.85 miles long and the trestle is 5.15 miles long.

The SMHB has been strengthened to withstand a Maximum Credible Earthquake (MCE). The retrofit is comprised of four construction phases:

• Construction Unit 1: Strengthen the west approach structure, Pier 1 and add Pier 1.k
• Construction Unit 2: Main span, including retrofitting the superstructure, substructure and pier foundations
• Construction Unit 3: Add over 7000 steel seat extenders, drive 20 piles to strengthen the transition section between the high rise and the trestle and add an expansion joint
• Construction Unit 4: Landscape the west approach and enhance public access

The high rise portion serves to facilitate marine navigation in the San Francisco Bay. It rises 140 feet above the Bay, and extends over the marine navigational channel, with a single 750' long span. One of the seismic retrofit items of the High Rise was the driving of several large-diameter hollow steel piles into the mud to increase foundation lateral stability. Ameron International supplied the piles for this operation. The piles were manufactured at our Fontana, CA facility and delivered to the jobsite.