Delaware Memorial Bridges Pin and Hanger Replacement
The Delaware Memorial Bridge is a twin suspension bridge connecting Delaware and New Jersey. Now over 50 years old, each bridge carries four lanes of traffic, and the lengths of suspended spans are 750, 2150, and 750 feet.
The stiffening trusses in the suspended spans are supported at the towers by links. There are a total of 16 tower links, and each has two pins and one compression strut. The current pins and pin plates, installed in the late 1980's, were found to have worn out. Therefore, the DRBA has initiated a project to replace existing tower links with a state-of-the-art bearing system.
To replace the tower links, CHI Consulting Engineers, LLC, as the contractor's engineer, designed a unique temporary jacking frame and hanger system to lift the ends of suspended spans and relieve loads from the existing links. The system comprises of upper and lower brackets and adjustable vertical link. The link is made of several parts that are bolted together by splice plates with slotted holes which allow for adjustment of hanger length during jacking. The hanger also has pins at its both ends so that it can accommodate the large longitudinal movements of the suspended spans. Local strengthening of existing connections and members were also carried out. The temporary hanger and brackets are robust, easy to install and remove, and have performed proficiently.