Can MSE retaining walls be used for landscaping features?

For any new development, aesthetics is important. How will the development fit in with the local environment? Does it make a positive or negative impact on the lives of those living and working nearby? On any sloping site, retaining walls can be a highly visible part of a new development. They do not have to be stark, brutal expanses of concrete – with thoughtful design they can be attractive landscaping features that add interest and beauty, enhancing the environment for all to enjoy. 

Tensartech TW1 stepped wall with planted terraces - Dubai. 

What are MSE retaining walls? 

Mechanically stabilised earth (MSE) walls, sometimes called reinforced soil walls, differ from reinforced concrete, masonry, or sheet pile walls in that they are ‘internally’ stable. All other types of retaining wall support or ‘hold back’ the soil retained behind the wall. MSE walls strengthen the soil behind the wall face so that it is internally stable. This is done by incorporating reinforcing elements, such as geogrids, into the soil as it is built up. The block of soil can stand vertically on its own, without external support The facing is no longer structural. It is not supporting the retained soil. Instead, the facing provides erosion protection and durability only. Different forms of facing are available, and the specific facing can be selected for any structure based on its aesthetics – what it will look like. 

What types of facing can be used on MSE retaining walls? 

Because the facing of MSE retaining walls are non-structural, there can be flexibility in choosing a facing. Varied materials, shapes and finishes are available. The designer can select a facing to suit the location, lifetime, purpose, and stakeholder requirement for the structure. 

Facing options include: 

• Modular concrete blocks with textured or smooth finish. 
• Masonry or natural stone. 
• Segmental concrete panels in various interlocking shapes. 
• Full height concrete panels with factory prepared textured finish. 
• Rock filled wire baskets or gabions. 

Tensar offers a range of MSE Retaining wall types as Tensartech® Earth Retaining Systems 

Can MSE retaining walls have a vegetated or ‘green’ facing? 

It is possible, but difficult to establish and maintain natural vegetation on a vertical face. Location, orientation, climate, and irrigation will dictate the type of vegetation possible. Expert local horticultural knowledge is important during the design and establishment of such walls.  

Where space allows, a vertical MSE wall design may be replaced by a steep faced MSE slope. By reducing the slope face from vertical to 70° or less, wider options for the establishment of vegetation on the face are possible. Appropriate selection of plants and in some cases, irrigation are essential to ensure the long-term survival and flourishing of vegetation. 

Tensar offers three Tensartech Systems for steep MSE slopes suitable for establishing vegetation. 

What landscaping features can be built using MSE retaining walls and slopes? 

On a sloping development site, MSE retaining walls and slopes can be used to provide grade separation, creating steps in the terrain to maximise the area available for development.  

High vertical walls can be visually intrusive. Their appearance can be improved and softened using terracing, where steps in the wall face are created by setting back successive sections of the wall. The horizontal terraces created in the combined structure can be planted with suitable vegetation to break up the wall and give a more pleasing, natural, appearance. In some cases, it is possible to reduce the vertical wall height by combining a lower wall with an upper steep slope with vegetation. Tensar’s Tensartech Systems are well suited for this form of combination structure. 

Why are MSE retaining walls used for landscaping? 

MSE retaining walls provide designers with wide options on geometry, appearance, and functionality. From a purely functional plane concrete finish to a highly textured factory produced panel, or a combination of natural stone-like blockwork with planted terracing and steep slopes. 

Facing types – As we have seen above, the range of possibilities is wide. Naturally vegetated facings, smooth concrete blocks, blocks with a fractured rock-like appearance, textured concrete panels, natural rock or masonry, timber crib, rock filled wire baskets, and many more.  

Geometry – It is easy to form tight concave and convex curves in MSE structures. Hard lines can be avoided in favour of more appealing curved structures. 

Structure height – There really is no reasonable limit on structure height. MSE structures have been constructed up to 60m tall. 

Fill type – With the appropriate MSE system, a wide range of soil materials can be used as fill material to form the wall structure. Site-won materials, recycled materials, mine waste and other waste materials may be suitable. 

Ease of construction – In most cases, no large lifting plant or specialist skills are necessary for construction. Structures can be built in sections as the works allow, using excavators and compaction plant. 

Cost - with no deep foundations typically needed, and with minimal plant needed for construction, the cost of MSE structures is consistently lower that other retaining wall types. 

Carbon Footprint – Compared to reinforced concrete walls, MSE walls have been shown to have a significantly lower construction carbon footprint. 

TensartechTW1 wall with curved shape

Turning hard landscaping to soft natural landscaping 

Retaining walls are essential on sloping sites to maximise development space. They are also needed for other grade separation conditions such as bridge abutments and wing walls. While plain concrete structures can be acceptable for some locations, most rural and urban locations benefit from a more aesthetic consideration. MSE retaining walls allow the designer to switch from the hard landscaping option to a more appealing, softer landscaping solution with the possibility of incorporating natural vegetation.  

Tensartech GreenSlope in city park- Hong Kong

How can I get a design for a MSE retaining wall? 

Tensar is the industry leader in MSE retaining wall systems. We can provide project specific advice, full engineering and construction support, including design, construction drawings, and site assistance, for our Tensartech reinforced soil structures.