9.7.5 Vertical failure of embedded walls
(1)P It shall be demonstrated that vertical equilibrium can be achieved using the design soil strengths or resistances and design vertical forces on the wall.
(2) As a minimum, the limit mode of the type illustrated in Figure 9.4 should be considered.
(3)P Where downward movement of the wall is considered, upper design values shall be used in the calculation of prestressing forces, such as those from ground anchorages, which have a vertical downward component.
(4)P The design magnitude and direction of shear stress between the soil and the wall shall be consistent with the check for vertical and rotational equilibrium.
(5)P If the wall acts as the foundation for a structure, vertical equilibrium shall be checked using the principles of Section 6.
9.7.6 Structural design of retaining structures
(1)P Retaining structures, including their supporting structural elements such as anchorages and props, shall be verified against structural failure in accordance with 2.4 and EN 1992, EN 1993, EN 1995 and EN 1996.
(2) As a minimum, limit modes of the types illustrated in Figure 9.5 should be considered.
(3)P For each ultimate limit state, it shall be demonstrated that the required strengths can be mobilised, with compatible deformations in the ground and the structure.
(4) In structural elements, reduction in strength with deformation due to effects such as cracking of unreinforced sections, large rotations at plastic hinges or local buckling of steel sections should be considered in accordance with EN 1992 to EN 1996 and EN 1999.
9.7.7 Failure by pull-out of anchorages
(1)P It shall be demonstrated that equilibrium can be achieved without pull-out failure of ground anchorages.
(2)P Anchors shall be designed in accordance with Section 8.
(3) As a minimum, limit modes of the types illustrated in Figure 9.6 (a, b) should be considered.
(4) For deadman anchors, the failure mode illustrated in Figure 9.6 (c) should also be considered.