Soil and Geotechnical

Typical Geotechnical Information Required for Design of a Swimming Pool

We often get asked by our clients what sort of geotechnical or soils information do we need in order to design a swimming pool. This article is intended to provide guidance as to the type of information normally provided by the project geotechnical consultant to the structural designer of a swimming pool.

The uniform loads of a swimming pool are relatively low (for example, approximately 500 PSF for a 7-foot deep pool), however, conventional ground-supported swimming pools are concrete shells and must be supported entirely by uniform soil conditions. Therefore, recommendations concerning the uniformity of support should be provided by the geotechnical consultant. In addition, if uniform support cannot be provided, mitigating measures are typically recommended.

The site conditions that have proven to be the most problematic are descending slopes in the immediate vicinity of the pool. Mitigation from the potential loss of uniform support of the pool due to slope creep and other descending slopes phenomena must be recommended. The code requirements can be found in CBC/IBC section 1808.7.3.

Pool Setbacks per CBC/IBC Section 1808.7.3

Pool Setbacks per CBC/IBC Section 1808.7.3

Soil Design Loading

Expansive soil conditions must be identified and if problematic, mitigating measures recommended. Pool walls are normally designed for active or at-rest soil pressure; therefore, the design values should be given in terms of equivalent fluid pressure for either an active or at-rrest condition, depending on the shape and configuration of the poo.

And finally, any other adverse geotechnical conditions that may potentially affect the pool must be identified and mitigation recommended. There are lots of other adverse soil conditions that can affect the successful construction and serviceability of a swimming pool. The geotechnical engineer should identify any unusual or unsuitable soil conditions and make suitable mitigating recommendations to be implemented in design and construction.