Earth Pressure Behind an Integral Bridge Abutment Under Traffic Loadings

摘要

Integral bridges are gaining increased popularity because of both economic and fast construction associated with the omission of bearing supports and expansion joints. In the present study, the earth pressure behind integral bridge abutments under traffic surcharges is investigated and compared with that induced behind the abutment of conventional bridges (with isolated deck and abutment) under the same surcharges. A numerical modeling has been developed to evaluate the dynamic earth pressure using the FLAC package. The Mohr-Coulomb criterion has been used to represent the soil behavior. Because the Mohr-Coulomb model is an elastic-perfect plastic model, the results of this study are valid only if the behavior of soil remains in the elastic ranges. The model was calibrated by direct measurement of earth pressure behind a physical model developed in soil mechanics laboratory to study the behavior of retaining walls. The induced earth pressures under static and cyclic conditions are evaluated and the pressure distribution behind the wall as well as the point of application of the total thrust was determined. The results have shown significant changes that happened in both quantity and distribution of earth pressure behind the abutment when using integral bridges. The details of findings and their causes will be discussed in the next sections.