Evaluation of Experimental Bridge: Massman Drive Bridge Over Interstate 40 in Davidson County

The Massman Drive Bridge is a 284ft. two-span continuous steel bridge over Interstate 40 in Nashville, TN. The bridge is an experimental design that unifies the construction economy of simple span bridges and the structural economy of continuous span bridges. The structural system involves bridge girders initially erected with simple supports at the center bent and abutments.

Before the deck is placed, an experimental connection is used to rigidly connect the two adjacent girders over the center bent. The experimental connection couples a cover plate in tension and two kicker wedge plates in compression. The kicker wedge plates supply resistance with direct bearing between each other and the compression flanges of the adjacent girders.

A total of 84 weldable strain gages were applied to three of the five bridge girders. The majority of the strain gages were placed at the connection on the plates and girder. Data collected during placement of the bridge deck concrete was used to evaluate the bridge performance under dead load. Several live load tests were later performed and will be reported by others. The data indicate that the three girders instrumented were continuous across the experimental connection. The two interior girders were found to exhibit similar behavior. However, the one instrumented exterior girder was found to have a reduced stiffness at the connection, as compared to the two interior girders. The effectiveness of the connection appears to be dependent on the erection of the wedge plates. A rationale for this behavior is presented but is not conclusive. Overall, the conclusion is drawn that the method works, in the sense that continuity over the center bent was achieved under the weight of the freshly cast deck.