Finite Element-Based Dynamic Analysis of a T-Beam Bridge with Skew Supports

Skew bridge footings are an important aspect of bridge construction, especially when dealing with bridges that cross over rivers, valleys, or other obstructions at an angle. The importance of skew bridge footings lies in their ability to provide stability and ensure the structural integrity of the bridge. When a bridge is constructed at an angle, the distribution of weight and load is different than that of a straight bridge. Skew pier bridges present unique challenges in modeling their fundamental frequency dynamics due to their asymmetric geometry and varying load distribution. Skew pier bridges have an asymmetric geometry that makes it difficult to model the fundamental frequency dynamics using traditional methods. Another factor that can affect the fundamental frequency dynamics of a skew pier bridge is the presence of irregularities in the structure, such as cracks, joints, or other defects. Factors such as irregularities in the structure, changes in the cross-section, or other local effects can also significantly affect the fundamental frequency of the deck and may require more advanced analysis techniques to accurately predict. Herein, a brief review is presented on the empirical and semi-empirical formulas for determining the fundamental frequency of footings and deck of skew bridges. Then, finite element analysis has been employed to examine how the skewness affects the bridge with T-beam deck slab’s fundamental frequency. A validation study has been carried out and a good comparison was observed. In order to determine the skewness effect, numerical studies have been conducted on T-bridge with support skewness ranging from 0° to 30°. Results show that the change in the skewness of supports results in the significant change of the fundamental vibration frequency.