 Diaphragm walls are expensive walls, but they save time and space and are also safe, so are widely used in urban deep excavations.In some cases, the lateral support which can be provided by the shoring wall alone is insufficient to resist the planned lateral loads; in this case, additional support is provided by walers or tie-backs.Walers are structural elements that connect across the excavation so that the loads from the soil on either side of the excavation are used to resist each other, or which transfer horizontal loads from the shoring wall to the base of the excavation.