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Precast retaining walls

Precast L-shaped retaining walls: A quick overview

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Precast concrete L-shaped retaining walls come in three different methods of construction:

  • Modular
  • Bolt down
  • Cast in

The modular type is used in material bays and is not suitable for retaining walls. While the bolt-down type is bolted-down to a designed foundation to take greater loads. The cast-in type is a heavy-duty retaining wall, and the base is cast into a raft, giving it greater strength.

Precast modular concrete retaining walls come in various finishes, plain, textured and coloured textured concrete. 

The design table for a bolt-down type retaining wall is included in the video. The design table has the wall heights at the top, the width, length, and weight of each L-shape, the foundation base width and depth, and the allowable surcharge amount.

From the design table, you can see the basic design principles, and from this information, we can carry out a cost analysis. We recommend that you watch the design video to learn more about the design process. We have put the cost analysis data into our retaining wall design and price guide, you can get all the data to develop your own retaining wall budget for all wall types within the guide.

We have included an example to work out a budget. From the designs in the table, we have created a bill of quantities and put together some costs. The budget is based on a wall over 50 linear metres long, so the wall has some scale. For example, if the wall is two metres high and one hundred metres long, that’s two hundred square metres with the rate is £254 per square metre. The table also gives you the labour, plant, and material calculations.

An L-shaped wall table of sizes and more information is available on the L shape wall type info page.

If you have a question, please use the ask a question or complete the price request form if you would like us to help you with a more accurate budget price.

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Kingpost retaining walls

Kingpost retaining wall design and UK price calculations: A quick overview

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A Kingpost retaining wall is a cantilever design. The posts are normally made from steel universal columns and are embedded into the ground.

The first step is to have the king post designed by a structural engineer. Learn more about the design process.

The soil information determines the size of the section and the embedment depth of the king post.

The technique for installing the posts is either to drive them or to vibrate them into the ground. If they’re going to be vibrated, the ground needs to be suitable for vibration.

Alternatively, the posts can be drilled in using an auger. The posts are put into the hole and then concreted in. In all cases, a piling contractor is required to carry out the post-installation work.

Once all the posts are installed, the panels are dropped into the channels of the steel posts.

The panels can be concrete or timber. Concrete panels can be plain concrete, textured, and colour textured.

Plain concrete panels are mostly used in industrial situations.

Kingposts are very handy for reinstating, repairing, or renewing existing retaining walls. Kingposts can be built very close to the existing retaining wall and don’t take up too much space. For an example, go to this case study.

The video includes a design table for the Kingpost retaining wall. They are approximate designs only. The actual section size and embedment design are carried out by a structural engineer using special software that analyses the soil data and load case. Learn more about wall engineering and design.

Kingpost retaining walls are very effective at low levels but become very expensive, over 3.5m in height, due to the section size and depth of embedment. For example, for a 3.5 metres height, the post length is 9 metres long with an embedment depth of 5.5 metres.

Every design is different. We highly recommend that you go to the retaining wall design page to learn more about the design process.

Head over to our King post wall type info page to learn more.

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Inclined retaining walls

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Stepoc retaining walls

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Reinforced interlocking block

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Gabion

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Masonry

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Criblock

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Flood defence

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Aquacast