An Investigation on the Lateral Earth Pressure Due to the Length Changes of the Integral Bridge Deck

Retaining walls are one of the popular earth structures for which a comprehensive recognition of soil-structure interaction is of importance issue. Among these retaining walls, the integral bridge abutment as a special type of retaining wall is subject to cyclic displacement, which is due to the daily and seasonal temperature variations. These bridges, known as bridges with rigid frames or joint-less bridges, are constructed so that the top deck is longitudinally continuous. The elimination of expansion and shrinkage joints causes a fluent traffic and a reduction in maintenance and repair of the bridge. In the other word, the expansion joints, which are widely used in traditional bridges, are removed in this type of bridges. Obviously, the imposed movement to the deck of bridge is transmitted to the top of the abutment, resulting in cyclic displacement of the top of the abutment. In this research, the finite element program Plaxis 2D was used to study the effect of cyclic displacements on the passive pressure of abutments integral bridge. Using this program, the analysis in many different conditions on a model abutment was carried out. To calibrate the numerical model, an innovative laboratory retaining wall model has been designed and constructed. The results of numerical model were calibrated using the laboratory test data. The results indicate that the passive pressure distribution, except for low amplitude displacement, is non-linear, which is due to the arch forming. In addition, the maximum passive pressure value along the wall is dependent on the magnitude of the wall rotation and number of cycle