Ruddlesden geotechnical


Cliff Stability Assessment

Cliff stability assessments might be undertaken prior to purchase, e.g. for a coastal property, on top of a cliff, or prior to development, e.g. for a development in an old quarry.

Cliff stability assessments might solely comprise a desk study and walkover survey, to identify the most likely mechanisms of failure.

This might be supplemented with an intrusive (borehole) investigation and/ or rope access work, to allow kinematic analyses to be undertaken.

If necessary, stabilisation recommendations are provided, which might include rock bolts, netting, de-scaling, monitoring and/ or maintenance.

Cliff stability assessments are also often required for conveyancing purposes.

Case Study

Cliff Stability Assessment, Dorset

There was a stability risk at a cliff-top site on the Isle of Portland, as indicated by a Phase 1 Geotechnical Assessment, previously undertaken by Ruddlesden geotechnical.

Ruddlesden geotechnical were commissioned to assess the potential for landslip, ascertain the likely landslip mechanism and causation and determine the relative risk of collapse.

Due to restricted access, rope accesstechniques were utilised to collect rock mass data for use in structural kinematic analyses to ascertain the likely failure modes.

The results of the kinematic analyses (and site observations) indicated the potential for rockfall and wedge-type failures within the top 10m of the cliff-top, confined to one particular geological unit.

Remedial measures, comprising rock-bolting and meshing, were recommended to maintain the existing cliff profile and hence long-term stability of the site.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust