FREYSSINET

FREYSSINET

FREYSSINET Arch, reaching height of 101.5 meters, is made of two converging tapering box trusses. After cables were connected, bridge loads were transferred from temporary supports built in the river.

With the 1,000-tonne steelwork pod in place, French engineers are now due to fine-tune 72 stay cables spreading down from the arch to support the Serebryany Bor Bridge. Cable stays have been in place since May, but final stressing had to be put on hold until after workers finished road surfacing and the restaurant module went up.

The arch spans nearly 140 m bank to bank, at right angles to the bridge deck it supports. That’s because the highway there is aligned along the river to avoid disrupting valuable real estate on its banks, says Christophe Blanc, export director with cable contractor Freyssinet International, Paris.

Due for opening in late January, the 1.4-kilometer-long bridge with 409.5-m main spans will carry the Krasnopresnenskaya motorway over the river on its way west to Moscow’s outer ring road.

Designed by architect by OAO Metrogiprotrans, Moscow, with structural work by NGO Mostovik, Omsk, the bridge’s arch arrangement is unique, claims locally based general contractor OAO Mosmetrostroy.

The highway also includes a twin-level tunnel under Serebryany Bor (Silver Forest) park in the 7-km stretch leading to the ring road, reports Mosmetrostroy.

The arch, soaring more than 80 m over the deck, is formed by two converging tapering box trusses. The trusses have roughly 10-m sides at the base, and they merge as they rise.

. Arch spans river to support elevated highway built over Moskova channel.

Freyssinet began installing cables early this year, allowing bridge loads to be transferred from river supports. The cables vary in length from 45.8 m to 198 m and 200 m and contain from 27 to 49 strands each.

Because of limited space, cable anchorages are made of welded steel plates projecting from the arch, says Guy Sevoz, a senior Freyssinet engineer. Their bearings are spherical to accommodate rotations caused by the restaurant’s weight.

With all main loads now in place, the French team must check tension in all cables and make necessary adjustments, says project manager Bertrand Garin. Excessive stresses will be relieved by adjusting cable lengths at the anchorage. To increase forces, the contractor will use the original strand-by-strand stressing. Finally, Freyssinet will install internal radial dampers in the 44 longest cables ahead of the bridge’s opening in the new year.