Subsidence Forum Training Day

Our climate over the past couple of years appears to be warming with increased temperature and longevity of the summer period and shorter, warmer winter periods with intense rainfall. Both of these increase the possibility of clay shrinkage subsidence with trees located within proximity to the property. Optera has been heavily involved in the promotion of copper impregnated root barriers as a cost-effective alternative to underpinning or piling where it is appropriate. Our demonstration will give a brief overview of the installation process whilst demonstrating a few of the recent interesting cases we have been involved with over the past two years.

With our multi-disciplinary team of geologists, civil, structural engineers and surveyors, we provide design and build solutions and specialise in underpinning and piling as well as slope stabilisation, landslip and retaining wall failure claims. We are able to provide the substructure solution, allowing our clients to engage a local contractor to carry out superstructure repairs or equally, we can provide a turnkey solution.

Majestic wine store

Following clay shrinkage subsidence of a majestic wine store in Milton Keynes in 2018, Optera were engaged by insurers to stabilise and rectify distortions in the brick clad portal frame.

The external column which supports masonry over a flying freehold had dropped which led to cracks in the high level brickwork and bed joints to open in the region of 40mm.

Optera designed and installed a series of 300mm diameter open bored auger piles around the supporting pad footing and jacked the column back to its pre-loss geometry. The resultant lift has closed all but minor bed joint opening which can be locally repaired.

The works were undertaken within 1 week and have been completed ahead of time and within budget.

The calvary to the rescue

Optera are progressing well with works to rebuild a turret on the corner of this grade II listed property in Rugeley. Having taken down the old tower and grubbed out the footings, a new piled ground beam has been installed to provide a robust foundation on which to rebuild.

Every brick has had to be hand-scribed and cut due to the irregular shape of the turret in compliance with the listed building consent. We have rebuilt part of the coach house elevation due to damage caused by the toothed brickwork of the tower rotten oak roof timbers have been cut out spliced locally to confirm with listing specifications

Working with our conservation engineer, Frank W Haywood and associates, Optera have sympathetically recreated the failed turret using a combination of innovative foundation engineering with traditional craftsmanship. The rendering will commence next week to bring this challenging project to a conclusion.

Risk to property

Optera has just completed work on our Huddersfield retaining wall. The wall forms the boundary with a disused quarry and with a 12m difference in ground levels, this was a serious undertaking!

Optera designed a bespoke remediation scheme, involving slope stabilisation with rock anchors and a restrained, reinforced-concrete retaining wall, faced with natural, local stone. We used lightweight EPS fill before reinstating the garden.

We are delighted with the outcome of this job, given its technical difficulty, access and safety challenges. If you have any complex or technically demanding projects, the team at Optera are here to help – contact

Continued Investment

At Optera Structural Solutions, we have developed a reputation for slope and bank stabilisation, encompassing retaining wall remediation and design.

Continuing our investment in plant efficiency, we have recently taken delivery of our latest Marini drilling mast, allowing us to safely and efficiently drill and secure hollow bar anchors into slopes and retaining wall structures.

By combining the mast with long reach plant, we are able to carry out projects without the necessity to physically work on the slope and therefore improving safety and efficiency.

We would like to thank our suppliers for their help and support through the build process and with the heatwave now behind us and stormy weather around the corner, it seems our new kit will soon be put into action.

Should you require information on this or any other Optera services please give us a call or visit our website at

Retaining wall

Our retaining wall project in Mertyhr Tydfill is coming to an end, on budget and ahead of schedule!

The before and after shots show what has been achieved in this technically demanding job, involving road-closures, build-over agreement and multiple properties.

Optera are delighted to have worked with Meadow Consultants Ltd. on this job.

The beautiful natural Welsh, Pennant stone facing covers all technical aspects of the soil-nailed slope stabilisation, the fully designed piled foundation, and the laterally retained structural stem of reinforced concrete blocks.

Please feel free to contact a member of the Optera team on where we will be pleased to discuss how we can help with your next project.

We even repair castles!

Optera, were engaged by Insurers to consider options to stabilise the turret on the corner of the grade II listed coach house to the Blithfield Hall estate.

The turret was destabilised by contractors working on a scheme for a deep pumping station installation. The subsequent movement within the turret has been significant, with cracks at the top of the 11m high structure now 120mm wide. The severity of the damage requires the structure to be taken down and rebuilt on a piled raft.

Working with our sister company, William Hunt Consulting who have organised listed building consent, detailed designs, surveys and a build over agreement.

Works will start shortly to take down the existing structure and reconstruct the turret, which despite its appearance is a later decorative addition to the coach house. The structure is built of brickwork with mock stone blocks scribed into the NHL render. Agreement has been reached to reinstate in a similar construction due to their low impact on surrounding infrastructure and property.

Substantial landslip

Optera have been appointed to deal with a substantial landslip at the rear of a property near Chepstow. Access presents one of the main challenges and following development of detailed plan, we had a successful day with a 50 tonne crane used to lift a 5 tonne excavator and some other plant onto the steeply sloping ground behind the property.

We will be installing a series of ground anchors and reinforced geo-mat to stabilise the failed slope and restore the Policyholder’s gardens to their former glory.

Merthyr retaining wall

Following the collapse to a retaining wall at the rear of terraced houses in Merthyr Tydfill, Optera were appointed to undertake reconstruction works.

Optera are delighted to work in conjunction with Meadow Consultants Ltd., who are acting as Contract Administrators and Project Managers, bringing together several different insurers for the affected properties.

The project was complicated by a 600mm diameter Water Authority drain running directly beneath the line of the wall, meaning that a piled foundation was required to prevent any damage being caused To make matters worse, the head of the slope failure was less than 2 metres from the rear elevation of two of the houses – to overcome this piles were used to support the properties before the face of the failed slope was secured using ground anchors and reinforced geo-mat.

A structural wall of reinforced concrete blocks was then built, being laterally restrained using further ground-anchors. Stabilised backfill was then placed behind the wall, with suitable drainage to prevent a build-up of hydrostatic pressure behind the wall.

Gardens and fences are being installed now and a natural Welsh, Pennant stone is being used to face the wall.

Engineering and artisan craft

Following a sudden collapse of a retaining wall into the road at Frenchay Village, Optera mobilised to make safe and rebuild.

Working from top down, the failed wall was removed, the garden contoured and the slope was enveloped with geomat, tied back to stable ground with hollow bar anchors and secured with galvanised plates.

Once the old wall was cleared from site, a new reinforced ground beam was dowelled into bed rock leaving rebar to continue into the Hollow concrete blockwork which was subsequently backfilled with C35 to form a discreet RC wall tied into a random stone face. The central line of anchors are secured to the outer face of the wall to provide additional moment resistance.

The blend of engineering and artisan craft on this project has left the policyholder and local villagers delighted with the finished product.