Allott and Lomax were appointed by the Transport and Road Research Laboratory to undertake the survey of bridge bearings under service conditions. Approximately 94% of the bearing groups (sets of bearings on a single substructure) were found to have bearings which had at least one defect. This report recommends that improvement to design, construction and maintenance of bearings, access and associated structural elements are necessary if premature replacement of the bearings is to be avoided. The report should be of interest to all bridge engineers whether they are involved in specification, approval, fabrication, design, detail, construction or supervision. A total of over 2500 bearings, representing all types and ages, were inspected in detail during a survey of 99 bridges within a sample area in the North West of England. This report gives the results of the survey and its conclusions. The report also gives a brief outline history of bearing functions and types together with an outline of bedding materials. It discusses access facilities and problems encountered. The factors affecting bearings are discussed together with the method of selection used for bearing inspection to ensure a broad sample of bridges. Recommendations are made for details of the bridge to improve accessibility to the bearings, bearing shelf and drainage. Methods for increasing the durability of the bearings and their protective system are recommended as is an improved fixing detail for stainless steel sliding plates. The need is established for improved installation, and maintenance checks to bearings, bearing shelf drainage and deck joints. Further research is suggested to obtain the sliding resistance of warped stainless steel in services conditions to give guidance for use in the assessment of bridges.

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