Technical Guidance Note (Level 2, No. 21): Design and detailing of base plates to steel columns

Although retaining walls have been the subject of two earlier Technical Guidance Notes; No. 8 (Level 1): Derivation of loading to retaining structures and No. 33 (Level 1): Retaining wall construction, their design has not been covered. This guidance note focuses specifically on the design of reinforced concrete gravity retaining walls. There are three different forms of this type of wall, all of which are designed to resist overturning and sliding failure. The primary difference between them is their height. The taller the retaining wall, the more likely that counterforts and beams spanning between them will be necessary. This note describes how all of these forms of retaining wall can be designed. (This article was updated in October 2016 to reflect errata issued since its original publication.)

This Technical Guidance Note is intended to act as an aide to those seeking to design an unreinforced masonry retaining wall. Following this guidance will prevent cracking and ensure that the wall performs as originally intended. The note will not cover the design of reinforced masonry retaining walls and variants of that form. Such reinforcement typically strengthens the wall itself against induced bending stresses and the wall’s geometry will therefore be somewhat different to that of an unreinforced retaining wall. The note will also not discuss the applied actions that a retaining wall will be subjected to, nor the construction of retaining walls. These subjects have previously been covered in the following Technical Guidance Notes: Level 1, No. 8: Derivation of loading to retaining structures and Level 1, No. 33: Retaining wall construction. It is assumed that the reader is familiar with the content of both these notes.

A significant-sized opening in a masonry wall will always require a lintel to bridge over it. This note offers advice on the different types of lintel that are available, their detailing requirements and their design.