February_1967 — Page 19

UNITED STATES

AMERICAN PCI'S 1966 AWARD WINNERS

FIFTEEN structures were selected by the American Prestressed Concrete In- stitute's 1966 Jury of Awards to receive equal honours. The awards, made

made each year, recognise "excellence in architectural and en- gineering design of struc- tures using precast and pre- stressed concrete, in the United States and Canada".

Singled out for special praise were the School of Journalism at Syracuse Uni- versity which in the opinion of the judges "will take its place as a classic of inter- national architecture", the Greenbriar shopping centre, Atlanta (see page ... ) and the Cascade Orchards Bridge near

Leavenworth, Washington.

Cascade Orchards Bridge, near Leavenworth, Wash. Arvid Grant and Associates, engineers Concrete Technology Corp., precast prestressed concrete and post-tensioning

S. I. Newhouse Communications Centre, Syracuse University's School of Journalism, Syracuse, NY.

I. M. Pei and Associates, architects King and King, associated architects Eckerlin and Klepper. structural engineers Stressteel Corp., post-tensioning

The structure is a five-storey (two underground) classroom building with an exterior facade of precast concrete wall panels featuring exposed aggre- gate: precast concrete window frames, and exposed precast concrete post- tensioned spandrel girders, utilising cast in place post-tensioned concrete

girders for the superstructure framing. The square roof area measures 112 ft. on each side; roof depth is 36 in. A 14 ft. cantilever is created at the corners by using an arrangement of 12 post-tensioned roof girders inter- secting at the four corners. A clear span of 51 ft. 6 in. is accomplished between interior columns.

A 175 ft. main span was required to bridge the swift Wenatchee River. with roadway curves in the mountain- ous area extending on to the bridge. Cascade Orchards Bridge consists of cast-in-place box girder end spans, projecting over the main piers and continued in the middle span by four precast prestressed concrete girders 110 ft. long.

This system permitted construction without falsework in the rocky and tempermental river. Based on com- parative studies, it was least in cost. also. The selected system supports a 32 ft. 4 in. wide superstructure with a 26 ft. wide roadway.

The bridge cost was US$186,000, even though the site is about 200 miles from heavy population, equipment and special materials supply centres. The actual structural cost was 20 per cent lower than the average of five recently constructed similar or larger bridge projects in the area.

Far East Architect & Builder February, 1967

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