Analysis on the mechanical properties of the crossbeam of a new ground anchor counterfort grille dam considering bearings displacement

Abstract

Aiming at the problem that the uneven deformation of the crossbeam of the new ground anchor counterfort grille dam under the impact of debris flow is easy to cause the overall damage of the structure, the crossbeam is simplified as a mechanics model of multi − span continuous beam supported on the grille columns, and the internal force calculation formulas of the crossbeam under the displacement and the local failure of the bearings are deduced. Combined with an example, during the process of bearings from the displacement to local failure, the internal force variation of the crossbeam are analyzed. The results show that when the single bearing is displaced, the mid − span bearing has the greatest impact on the internal force of the crossbeam. When the two bearings are displaced at the same time, the two side − span bearings have a greater influence on the internal force of the crossbeam. When three bearings are displaced at the same time, the influence on the internal force of the crossbeam is the smallest. When the single bearing fails, the failure of side − span bearing has the greatest influence on the internal force of the crossbeam, the mid − span bearing failure is second. Therefore, the reinforcement at each bearing of the crossbeam should be considered to meet the force requirements after the internal force redistribution in the design, so as to ensure the safety of the structure after the positive and negative bending moment of bearing are converted. In addition, when displacement or failure of bearings occur, attention should be paid to meet the limit requirements of structural deformation and stability. The research results can provide a theoretical basis for the reliability analysis of the new ground anchor counterfort grille dam.