ANALYSIS METHOD FOR PILE-ANCHOR RETAINING STRUCTURES BASED ON THE DISPLACEMENT MATRIX METHOD

The pile-anchor retaining structures are simplified as a continuous beam in load-spring model. The pile is simplified as elastic foundation beam, while the active earth is converted to load system, and the anchors and the passive earth are simplified as a spring system. The spring stiffness has been determined by Mindlin's solution in semi-infinite elastic space under horizontal rectangular load, and the spring factor is closer to the actual situation because of reduced rate of increasement in spring stiffness with depth. According to this model, the matrix analysis method is presented, with the consideration of the effects of excavation process on pile deformation and internal forces of anchor. It proves the matrix analysis method to be convenient and feasible through a practical example.