Combining the concept of mechanics with practices, introducing engineering cases to explain relevant knowledge points can enhance students' interest in learning and improve the ability of students utilizing theory in practices. Bridge, bridge supports and foundations is described. The mechanical models of the pier that suffered vertical impact and horizontal impact are simplified respectively. To the simplified pier model, with and without the rubber isolation bearing, or the anti-collision pier, comparative analysis is carried on the deformation and dynamic load coefficient of the pier. According to the conservation of energy, the related problems are analyzed and discussed, and improve the understanding ability of students to related mechanics concept.