RETAINING WALL TYPE

King post case study (2.5m high)

Our client made contact for support on a king post retaining wall design project for their project in Stourbridge.

The wall length was 19.5m, 16.5m and 22m. The wall height was 2.5m

The soils were loose to medium dense becoming medium dense red and orange-brown gravelly sand for 6mm, then dense becoming very dense brownish red sand with some becoming friable sandstone. Grading into very weak brownish red sandstone to a depth of 2.1 and the end of the borehole.

To learn more about king post retaining walls click here.

Wall design – embedment depth

The design of the retaining wall was completed using GEO5 Sheeting Check software from Fine Software. All calculations are completed in accordance with BS EN 1997, BS EN 1993 and other relevant UK and European standards.

The results of this analysis are presented in the table below;

 

 

 

 

King post retaining wall design

Material purchase

To obtain the best prices for the project we prepared a working drawing to show the post details and all accurate dimensions.

Two posts were used at the corners as detailed.

We then prepared a material schedule for the posts and panels.

King post setting out sketch

Budget pricing

Using the material schedule, we obtained quotations for the steel and concrete panels from our supply chain. The project was priced in June 2022.

We then built up a m2 rate for the project. The calculation for the built-up rate is below:

Steel

Cut to length and delivered 6.9 ton @£1,700 ton = £11,730

£11,730 / 139.5 = £84.98 m2

Panels

Panel proposal from supplier for the supply and delivery of 139.5 m2 – £16,412 / 139.5 m2 = £117,64 m2

Built up rate

Steel £84.98
Panels £117.64
Concrete £6
Plant £50
Labour£50

Total £308.62 m2

Budget £308.62 x 139.5m2 = £43,052

The above budget is for self-build add 25% to cover risk, overheads and profit for a specialist contractor to carry out the work for you.

The steel is black i.e. not protected. The embedded steel will be protected from the concrete, only the top of the steel is required to protect. An epoxy resin paint system is recommended.

Exclusions

The prices above do not include any excavation to form the retaining wall and no stone filling behind the retaining wall. The rate only includes the supply and construction of the retaining wall.

Note

Every project is different regarding soil type, scale, site access and location. Every project needs to be priced from the structural engineer’s calculations, specifications, and drawings. Budgets are July 2022 prices.

Our services

We have a supply chain of reliable suppliers and contractors for all types of retaining walls that cover most of the country. We offer a service to design your project and obtain the best prices, saving you a lot of money and bother.

Please complete the form on our contact us page for specific help and support.

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