Citation

Walkinshaw JL. Transp. Res. Rec. 1978; 678: 6-12.

Copyright

(Copyright © 1978, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The design of bridge superstructures is usually based on the assumption that less than 25 mm (1 in) of movement will occur within the substructure. Consequently, the foundation engineer must find soils at a proposed site of sufficient bearing capacity to limit movement to this small value. Often the movement criteria will dictate the size or depth of the foundation, thereby increasing its cost needlessly if the criteria established are too strict. The purpose of this survey is to document field performance of various structures that have moved and obtain an evaluation as to the acceptability of these movements by various state highway agencies. The 35 structures reported in this paper include 54 movements of structural elements. Sixty percent of these represent movements at the abutments and 40 percent represent movements at piers. Although some very large vertical movements were reported tolerable for some of the older structures, movements in excess of 63 mm (2.5 in) within the structure were usually considered objectionable from a rideability viewpoint. Horizontal movements in excess of 50 mm (2 in) usually caused structural distress that was considered harmful. Recommendations are made to improve reporting procedure and make use of available material. Emphasis is on more thorough involvement between designers and maintenence crews in solving movement problems.