Geotechnical intervention

Soil nails and rock anchors

Optera are able to offer slope stabilisation in previously untouched slopes which have become unstable or weak, or in retaining walls where the earth requires additional stabilisation. Our operatives are harness trained and can use hand-held equipment or larger slide drills to drill and stabilise a slope with either soil nails or rock anchors, depending on the geology. If required, we can also secure the slope with specialist geotextiles or steel mesh fabrics.

Slope instability is normally caused by erosion or pore water pressure increases due to periods of persistent heavy rainfall. As the effects of climate change become more apparent, the statistically unlikely 1-in-100-year-storms now appear to be occurring more frequently. Optera’s team of experts are therefore ensuring that our solutions not only stabilise the slopes, but also include a scheme of supplementary drainage which captures water at the top and on the slope and conveys it downwards and away in a controlled manner. With this approach Optera are able to provide long-lasting solutions.

Optera are also a Platipus-approved installer and offer a cost-effective alternative to large-scale civil engineering contractors in circumstances where these ground anchors are required.

Subterranean voids

Optera’s engineering specialists are frequently called out to investigate and design bespoke solutions to a variety of ground failures, including: sink holes, mine shaft failures and disused well collapses. Although the causes for these vary depending on the geology of each site, they are all triggered by a loss of support for the overlying strata which can then collapse, often without warning. Such occurrences require specialist investigations and engineering solutions, which Optera are expert at delivering.

Our extensive experience of dealing with mine shaft collapses and sink holes gives us a unique insight into the technical complexities of remediating such situations. First and foremost, we offer rapid deployment to investigate each case in order to establish the extent of the feature and what immediate steps need to be taken to ensure that no lives are put at risk. Following our investigations Optera can then design and implement a bespoke solution. This often involves filling the void with clean stone or a lightweight foamed-concrete which provides a safe working platform on which to undertake structural intervention. Our solutions regularly incorporate retaining walls which are built against the house to prevent any future vulnerability. Any remaining depression following structural remediation can be levelled out with a combination of lightweight dense polyurethane blocks and land drainage to remove ground water, reducing the risk of future occurrence. Once filled, we can then complete the project with high quality repairs to the property, should they be necessary.