Numerical simulation of grillage flexible supporting structure with prestressed anchors for an excavation

Grillage flexible supporting structure with prestressed anchors is commonly adopted in the projects of deep excavation, but there is no report for its numerical simulation analysis till today. Based on an engineering example, by using the FEM software ADINA and choosing reasonable constitutive models, the numerical simulation for grillage flexible supporting structure with prestressed anchors for an excavation is performed. The results show that the final maximum horizontal displacement appears at the top of excavation, and the prestress values as well as the action positions of the prestressed anchors have significant influences on the horizontal displacement of wall facing. With the increase of excavation depth, the ground surface settlement and the bottom uplift of excavation increase at the same time. The axial forces of anchors increase with the increase of excavation depth, which are on curve distribution along the length direction. The connection line of the points of the maximum axial forces is similar to the slipping surface curve of excavation, and the maximum values of the axial forces of anchors appear bow-shaped distribution along the direction of excavation depth. The numerical simulation shows that the grillage flexible supporting structure with prestressed anchors has obvious effect on the deformation control for deep excavation, and it is worthy of further promotion and application.