A REALISTIC APPROACH TO SEISMIC EVALUATION OF CONCRETE BRIDGES

In the Northeastern U.S., the risk of seismic activity is low to moderate. Still, there should be more testing and understanding of the behavior of reinforced concrete under lateral loading. Engineers in the Northeast measure vertical service loads and extend that measurement to seismic capacity assessments which usually fall short of the required flexural and shear capacity. This does not provide an accurate and realistic picture of the seismic capacity of columns and bridges. Many engineers have begun to wonder if brittle structural components are more likely to be the problem areas. The failure of component sections or parts will produce a greater likelihood of displacement and that is seen as the critical area for further study. Knowing just how far a bridge can be "pushed" provides a clearer picture of the possible effects of low to moderate seismic activity in the Northeast.