Houston Street Viaduct - Dallas, TX - U.S. National Register of Historic Places on Waymarking.com

"The reinforced concrete viaduct between Dallas and Oak Cliff is 6,562 feet long, 56 feet wide overall, and has a roadway of 44 feet with two 4.5-foot sidewalks. It is made of fifty-one, 79'6" arches, a steel girder 100 feet in length spanning the Trinity River, and 16 panels of concrete bents and girders next to the approaches. The crossing of Lancaster Avenue in Oak Cliff from the last pier to the abutments consists of six panels of girder design. Beyond this is an earthen approach 787 feet in length.

Laying of concrete was facilitated by a rigid tower and chute moving on a track next to the viaduct. Bents and girders were poured continuously using two shifts when necessary. Slabs and floor members were also continuously poured. Because of a drought during the construction of the viaduct, raw sewage was used in the concrete mixture.

All arch piers rest upon timber piles except for the easternmost abutment arch, which rests upon bedrock a few feet below the ground surface. Piles were driven into the ground and concrete was poured around them for a firm foundation.

Arches rest upon cross walls which are supported by three columns. Vertical supports rest upon cross walls and reinforced concrete arches. These vertical members support longitudinal girders which in turn support the floor slab.

One of the extraordinary features of the Houston Street Viaduct is the use of rocker bearings for girders. On one end, the longitudinal girders are rigidly attached to the reinforced corner brackets. On the other end, the girders rest in a socket formed by two bent copper plates extending the full width of the girders. The lower plate rests on the cross girder and the upper plate is fastened to the longitudinal girder. Both plates are connected by reinforcing bars just above each socket, but a cleavage plane is left between them to permit rotation. All girders are, therefore, discontinuous and designed as simple beams."