Concrete Retaining Structures
Segmental Retaining Walls come of age
In the UK, Segmental Retaining Walls (SRW) have been rapidly gaining popularity in recent years. For many years, the United States had led the way in the development of such products but the fastest growth in sales and projects is now occurring in Europe, often with the European and American companies working together to share their experience and expertise.
SRW’s have proved to be immensely versatile. At their simplest, they are gravity retaining walls that can be quickly and easily built by DIY enthusiasts in their garden without special skills or the need for using mortar or adhesives. However, with the assistances of engineers, SRW’s can be utilised in a wide variety of more demanding situations. These larger walls typically comprise of a mass of granular soil reinforced with a polymeric geogrid and faced with hydraulically pressed ‘semi-dry’ concrete facing blocks and where required can be built to heights of 10 metres and upwards.
The appeal of SRW’s stems from various benefits. The designers can have confidence that the concrete blocks and the geogrids are made under carefully controlled quality systems. Cost benefits accrue because the onsite soils can often be used as backfill meaning the movement of material on and off the construction site is limited. The erection process is generally very quick compared with the other methods of building a retaining structure along with the fact that there is no need to co-ordinate the availability of skilled trades such as steel fixers, joiners or bricklayers. The finished structure can be designed for an extensive design life; 120 years is a common benchmark and some systems have also completed assessments by independent bodies such as BBA.
However arguably the most compelling reason for the rapid adoption of SRW’s is their versatility. With the innovative manufacturing techniques, natural rock-like textures are available and there is a vast variety of colours which can be considered to help the finished wall blend with or compliment its surroundings. Furthermore, the latest types of SRW are designed so that as well as creating straight walls, they can be used in curves, corners and steps and even finished with matching cap details.
Designing SRW’s is well documented. Early in the development of SRW structures, the US based National Concrete Masonry Association took a lead in developing and setting standards for design, construction and testing. Its Design Manual for Segmental Retaining Walls first appeared in 1993 and rapidly became (and still remains) the definitive guide for Engineers and Architects considering using this method of retaining wall construction. Of course, the developers, manufacturers and distributors of SRW systems have experienced engineers on site who can be on hand to assist throughout the design and construction process and many have developed powerful design software to streamline the design calculation process.
In summary, SRW’s have come of age. Millions of square metres of walls are being built every year using this technology around housing developments, in landscaping and civil engineering projects and it’s easy to see why.
In the UK and Ireland, Anchor retaining wall systems are marketed by Acheson & Glover specialises in retaining structures, soil reinforcement and erosion.
Read more about how our retaining walls work on our retaining wall page below:
