EVALUATION OF SHEAR PLATES AND GROUTED SHEAR KEY JOINT PERFORMANCE OF A THREE-SIDED PRECAST CULVERT

The effectiveness of shear plates and a grouted shear key joint system in providing load transfer across three-sided bridge sections is evaluated. Because of the flat-top culvert geometry accommodating pavement directly on top of the sections, it was important to determine the structure's response to differential deflections between adjacent sections when subjected to live loading. Prompted by research that evaluated shear plates on tongue-and-groove jointed box sections with spans up to 12 ft, the project focused on a three-sided structure with a substantially longer span (30 ft) and a grouted shear key joint system. Deflection results are presented for various combinations of shear plates and the keyed joint when subjected to simulated live loading. The results indicate that the grouted shear key joint system is an effective means of distributing the load between the precast sections. The addition shear plates does not enhance the structural response of the grouted structures. Shear plates alone are ineffective.