Willerby School, Hull

Our brief

Lithos were commissioned by BAM Construction to undertake a site investigation at the site of a school in Willerby near Hull which is to be developed and enlarged to support increasing student numbers.  The development will comprise a 3-storey classroom complex and a sports hall.

Site characteristics

The site had previously been appraised by another consultant, and was expected to be underlain by firm to stiff Glacial Till, with Chalk bedrock at about 8m depth. However, some ambiguity remained with respect to allowable bearing pressure beneath proposed pad foundations.

What we did

Lithos’ ground investigation included 8 trial pits and 4 cable percussion boreholes in early 2015.  Hand vane testing and SPT testing confirmed that cohesive deposits beneath the site were firm to stiff from depths of around 1m.  Laboratory analysis of undisturbed samples enabled Lithos to determine site-specific geotechnical design parameters, and also provide advice about pad dimensions after considering proposed column loads, bearing capacity, and anticipated settlements.

The outcome

Lithos were also asked to re-present and supplement existing site investigation data in order to prepare a more robust report, suitable for submission to the local authority to enable the discharge of ground-related planning conditions. Lithos will also provide BAM with ongoing geotechnical consultancy support during the build programme.