Memorandum

On April 13, 1994, I met with WSDOT Bridge Maintenance Supervisors at their annual meeting in Selah. Many of the attendees expressed their concern about eliminating expansion joints on longer bridges. Almost all districts indicated they were having problems with bridge movements at the end piers and approach slabs where a long bridge was built without expansion joints within the spans.

In order to mitigate this problem, the following general criteria should be followed:

Steel Bridges:           Use L-Abutments with expansion joints at ends for multiple-span bridges.
                                For single span bridges, expansion joints may be eliminated with the
                                approval of the Bridge Design Engineer. Whenever the bridge skew
                                exceeds 30 degrees, the Expansion Joint Specialist and the Bridge
                                Design Engineer should be consulted for recommendations and approval.

All Concrete Bridge: Use L-Abutments with expansion joints at ends when bridge length
                                exceeds 400 feet. Whenever the bridge skew exceeds 30 degrees,
                                the Expansion Joint Specialist and the Bridge Design Engineer should
                                be consulted for recommendations and approval.

Note: The use of intermediate expansion joints should be avoided, where possible.

This criteria should be incorporated into all preliminary bridge plans and new designs effective May, 1 1994. If you have any questions or comments, please let me know.

CCR

cc:        J. VanLund

            Y. Fahoum (BDM, Chapter 8)

            F. Higgins