The Non-linear Dynamic Buckling Analysis Of High Pier Under Impulse Loads

Resent years, our country increased constructions of the fundamental establishm- ent constantly, mainly in the road, the railway and the bridge. Due to the complication and oddity of the terrain, the high piers are always used in the engineering when the construction through in the high mountains and cangons, especially in the remote mountain areas and the western. Many difficulties can be proposed in the construction and design of the pier.As the high pier mainly subjecting to axial load, the stability problem is the important problem of the high pier under the impact on the top or the influence of the earthquake. So the research of the dynamic characterity and the dynamic stability of the high pier is of great importance when under the impact load. In this paper, includ- ing the shear deformation and large deformation, the basic nonlinear dynamic equations are established. Then the time-dependent equations of the high pier under the impact are founded by using the Galerkin method when deflection shape functions assumption applied. The result to this problem is obtained by using the four-order Runge- Kutta method. The theory is offered for the engineering application. The following contents are mainly discussed in this paper.(1) The basic conspectus and theory of the buckling of the high pier is introduced firstly. According to the buckling property of the pier, the control equations of the buckling of the high pier is established including both the geometric and physical nonlinearity. The Runge- Kutta method, the program design and the basic theory of the Galerkin method are introduced in details in this paper.(2) Under the triangle-shape impact and rectangle-shape impact load, the dynamic buckling of the concrete high pier with two endpoints simply supported are investigated respectively. The deflection curves of the pier under impact load are presented. The dynamic buckling routes are depicted. The influence of the geometric parameters and load parameters on the dynamic buckling of the pier are discussed.(3) Under the triangle-shape impact and rectangle-shape impact load, the dynamic buckling of the concrete high pier with one endpoint simply supported and the other fixed are investigated respectively. The similar dynamic bulking rule to both the two endpoints are simply supported are observed, and the differences of the buckling route form the two endpoints when simply supported are compered. Some valuable references is presents for the engineering practice. (4) Under the triangle-shape impact and rectangle-shape impact load, the dynamic buckling of the concrete high pier with two endpoints simply supported is analyzed as the bi-linearity constitutive model is adopted. The displacement response curve of high pier under the impact load are present. The influence of the plastic deformation on stability of the high pier is analysed.