WHERE SECTIONS OF RETAINING WALLS ARE MUCH REDUCED, THE ANCHOR RODS ARE EMBEDDED IN CONCERT BLOCK OF SUFFICIENT AREA AND SITUATED BEYOND PLANE OF RUPTURE.

RETAINING WALL WITH BACK-ANCHORING:-- In case the earth to be retained is of considerable height, anchor rods are provided at the back of the wall approximately at 1/3rd the height of the Retaining wall to reduce the Bending moments and Shear force in the vertical slab where by sections are much reduced. The anchor rods are embedded in concrete block of sufficient area and situated beyond plane of rupture so that the frictional force on the concrete block exceeds the tension in the rod. The area of rod is obtained by dividing tensile force in rod, by allowable stress which may be taken as 140 N/mm square. The tension in the rod is found by assuming the Bending moment at the foot of the stem, as zero. The rod is connected to the stem through vertical beams or horizontal beams. In case of connection of tie rods to vertical beams, the stem is designed as a continuous slab between the vertical beams. A vertical beam is designed as cantilever. Above the rod it is subjected to earth pressure taken by the stem between two beams and below the rod it is subjected to earth pressure taken by the stem between the beams and tensile force in tie rod. In case of connection of rod to horizontal beams the stem is designed to act as cantilever subjected to the earth pressure above the horizontal beam. The portion below the horizontal beam is designed as cantilever subjected to earth pressure and the force in the rod. The horizontal beam is designed as a continuous beam supported by the tie rods. The base is subjected to load of earth on the heal, self-load of the stem and base and any difference in horizontal earth pressure and the tension in the tie rod. The tie rod is fixed at h/3 for design consideration of the tension in tie rod, areaof steel required and the area of anchor block.