A photo showing the winches lifting a 28 m (92 ft) superstructure segment from the barge into place on the bridge. Cantilever construction requires the main and side span segments to be assembled simultaneously to prevent large moments from overstressing the towers. Construction of cable-stayed bridges often requires more engineering than the design of the finished bridge.
In this photo, the far ends of the box girders are supported transversely with cables while the whole assembly is raised by the winches. Once the segment is in place and supported by cable-stays, the additional supports can be removed.
I recall that this bridge cost about $300 million US, which was reported as high, but seems pretty reasonable for a kilometer long main span bridge structure to me (the second longest cable-stayed bridge in the world). Construction prices fluctuate depending on how much work is out there. A few years ago when this bridge was being built prices were high, but now there is less work and prices have dropped (at least in California).
Cable-Stayed Bridges - Stonecutters Bridge (9) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.