The $605.8-million Tatara Bridge over the Tatara Strait between Ikuchi and Omishima islands is part of a $27-billion project that provides 18 major bridges and 150 km of expressways to link the islands of Japan's Inland Sea.

HSBA divided superstructure construction between two ventures led by Mitsubishi Heavy Industries Ltd. and Ishakawajima-Harima Heavy Industries Co., both Tokyo. They used similar procedures to erect towers, deck and cables.

Each tower was made up of 23 prefabricated elements that were barged to the site and welded in place. Each unit averaged 12 m in height and weighed 140 tons. The towers are an inverted-Y shape with the legs slanting inward below the deck. The main span's deck, composed of 20-m-long segments, was cantilevered toward the center, pacing erection of the cables. Because of the geology of the site, the end spans are not only of different lengths, 270 and 320 m, but short in proportion to the length of the center span. Half the length of each end span was prefabricated as a single piece and lifted into place by floating cranes.

There are 21 cables spreading out from each side of each tower. They range in diameter from 108 to 170 millimeters; the longest is 460 m. The bridge is designed to withstand winds of 63.6 m per second and an earthquake of 8.5 magnitude. To eliminate the turbulence from wind blowing on rainwater flowing on a cable, the surface of the longest cables are dimpled to break up water rivulets. The five longest cables in each set have dampers at the deck connection.

An Industry in Mourning
With one year left to go before its opening, Chek Lap Kok Airport was the world's most ambitious public works program in 1997, at a time when the bumpy relationship between Great Britain and China culminated in Hong Kong's return to China. Design and construction of the $21-billion airport was to be completed in a six-year time span on the tiny island of Chek Lap Kok. It was leveled and expanded to 1,248 hectares to accommodate the world's largest terminal, at 516,000 sq meters. The 39-gate terminal was to be the centerpiece of the airport, built on a 1,248-hectare platform. The terminal has a 700-m-wide entrance and 490-sq-meter concourse and gate area. Its eight levels are encased with glazed exterior glass walls over the 4.4-km perimeter of the structure (ENR 7/7/97 p. 30).

I-15 Follows a New Road
Utah began evaluating proposals for a $1.36-billion job that incorporated design-build and performance-based contracting into a public project. The rehabilitation of Interstate 15 through Salt Lake City was unique, as it was to be the largest project under a federal program that evaluated and tested innovative contracting schemes. The contractor with the best solution for completely tearing out and reconstructing 16 miles of highway and 137 bridges in 4 1/2 years would be used. The losing bidder would receive a $950,000 stipend for its efforts. Utah was praised by contractors for its willingness to experiment with design-build and a contract based on more than just price (ENR 1/27/97 p. 10).

Making Way for More Water
The nation's largest earthmoving job, which turned up an Ice Age fossil, had crews excavating and backfilling 250,000 cu yd per day, one of the highest rates ever in the U.S. The Los Angeles-based Metropolitan Water District's Eastside Reservoir Project was planned to help supply water to the region in case of an earthquake. The $1.9-billion job resembled a "mining operation in scale and cost," and would increase the district's surface-storage capacity, doubling the districts supply to six months. mwd imports water from northern California and the Colorado River. Two large earthfill dams will impound an 800,000-acre-ft lake covering 7.5 sq miles. It is at an elevation high enough for water to be conveyed by gravity to customers. The reservoir is located on a 4,500-acre site (ENR 8/4/97 p. 24).