Structural design calculations and general advice are provided in accordance with various national and international standards relative to the product and its application. Please go to the relevant product and our calculation tools.

Most culverts, underpasses, conveyor tunnels and stormwater tanks are designed in accordance with Highways Agency Standard BD12/01 which also encompasses durability requirements.
To undertake a design calculation we need the following information:

• Live load
• Dead load/depth of cover
• Diameter or span
• Design life
• Environmental classification

For bolted plate structures of spans greater than 8m, the Kloppel-Glock method is used.
The same input data as above is required.

For installing attenuation and drainage tanks or water storage systems, we help customers by carrying out two essential hydraulic calculations:

1. Establishing the correct size and volume of stormwater tank using a range of methods and standards
2. Establishing the correct size of soakaway using the BRE Digest and/or Microdrain Source Control

Contact us to advise you on the appropriate solution for any site and requirement, and to comply with recommendations contained in the SUDS manual.

The capacity and layout of a soakaway depends on many of the factors influencing a conventional retention system, except that the water is absorbed into the surrounding ground.

We can design systems using BRE Soak or CIRIA Report No R156 and CIRIA C697. The infiltration coefficient of the soil is very important and must be established by site testing.

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