Cotswold Canal Trust – Bank Stabilisation

Cotswold Canal Trust got in touch via our website in regards to a bank on the Thames and Severn canal that needed stabilising. They had heard about us from one of our previous customers, who we helped with the Dursley Tree House project featured on Grand Designs in 2016.

One of our team visited the site at Ham Mill Lane in Stroud to discuss a solution to stabilise the failed canal bank with the volunteers from the trust. A screw piling solution to support the gabion retaining structure was developed with their Structural Engineer to install 60R screw piles both vertically and raked at 45 degrees using our 400H handheld anchor driver. This stabilisation would allow the Thames and Severn canal to be dredged. The work also formed a small part of a wider effort to eventually reopen the canal for public use.

As a result of our solution and the volunteer team's hard work, more material was prevented from falling into the canal, and they were able to support an adjoining neighbour’s garden from falling further down the hill.

The volunteers were inexperienced in screw piling so an engineer attended site to provide training on the safe use of the equipment. We assisted them with safe working methods to allow them to pile at 45 degrees on a steep slope.

“We had a good session of familiarisation training with one of your engineers on Wednesday . I would just like to say how pleasant and helpful he was, it was a pleasure to work with him.”

Bob Ambury, Cotswold Canal Trust

We enjoyed working with the Cotswold Canal Trust as the team are all volunteers, so they were keen to learn and get stuck in.

We are now assisting the trust with the design of a further 4m high gabion retaining wall which will be supported on screw piles. We are keen to see how this second project progresses and hope to continue to be involved with the wider project of re-opening the Thames and Severn Canal for public use.

If you have a project in mind and are considering using screw piles due to their many benefits, please don't hesitate to get in contact with us.

Garden Structure – Karen’s Childcare

ABC Anchors were approached to assist in a solution for foundations at Karen’s Childcare. They wanted to expand the outdoor area for the children and the available space had a few challenges to overcome.

Site access and foundation positioning was limited, so screwpiles were identified as the best solution by the Client. The piles were to be installed behind a retaining wall and next to a boundary wall; therefore they needed a vibration free and non-destructive installation method to prevent damage.

We used our 400H Handheld pile installer due to a lack of space, ensuring a smooth installation. There was no damage to the wall, as the piles transferred load from the structure to below the wall to prevent it failing due to the additional load of the garden structure.

Our lightweight garden piles were specified by the team here as they were ideal for supporting the low loads (up to 2 tonnes per pile) and are suitable for most soil conditions. The 8 pile system was installed in a day and once finished, the structure could be built instantly, as screw piles are unique in not requiring any wet trades. This removes the time delay in the build for curing.

Our customer was happy we were able to find a solution to building on this tricky site and we are pleased to say they have now completed their garden structure.

“ABC Anchors provided an 8 screw pile solution in a difficult location that was installed by a very professional team of two. it is a great system that is providing support to our Outdoor Structure which was designed, manufactured and installed by Beyond Timber of Dinnington.”

David Ellison, Karen's Childcare

For more information on our services, or to talk to us about your own project, please feel free to contact us. If you have any questions on using a screw pile system, our FAQs may provide the answer!

RD Residential – Garden Studio

This project involved the construction of a timber-built garden studio in West London.

Screw piles were a preferred choice for the foundations, as the proposed location for the structure was at the base of a mature tree and in a tree root protection area.

The access to the site was also restricted allowing only hand held equipment to be used.

Both the customer and contractor for the build were new to screw piles and had been referred to us by their structural engineer, all the information was provided to each party and the system and method was approved.

The 60R product range was chosen due to the loading and the structure, and the unique 400H Hand Held anchor driver was chosen for the installation. The ground conditions varied across the site so additional extensions were used to achieve the required torque for the design load.

The foundations for the garden studio were successfully completed and the contractor was very happy with the service received:

“From start to completion ABC Anchors were a pleasure to deal with, very supportive, and easy to talk to when queries arose.  We would highly recommend both their products and service and will definitely be using them again for any piling needs we have.”

Ed O'Donnell, RD Residential

Underpinning from Inside a Building

Problem

The Customer has experienced subsidence of the property due to trees in the back garden and fluctuations in ground moisture levels, causing the walls to move and cracks to appear.

Access to the outside wall was not possible so underpinning needed to be carried out inside the building. In addition to the subsidence, the customer was also looking to redevelop the extension from single to two storeys. 

Solution

Using the ABC 400H hand held torque and keeping the powerpack outside the house. The Piles were installed quickly and quietly, underpinning brackets were then fitted and pre-loaded to design load. This was then back filled around the piles and the floor reinstated. The building is now ready to be developed to a two storey.

Julia’s House Children’s Hospice

This project involved installing 6 quantity 60RL* screw piles to support a small wooden Cabin.

Screw piles were the preferred choice of foundation for two reasons, firstly as there were tree roots and secondly, the ground dropped away by up to 1meter in some pile positions.

Using our 400H hand held torque head 2 rows of 3 piles were installed with the front 3 piles being installed to ground level and the back 3 protruding above ground level by approximately 1m.

As a precaution a cross brace of the 3 rear piles was designed to be used to ensure lateral stability.

The piles were terminated with a flat 200mm x 300mm plate which allowed easy connection of the steel ring beam for the cabin to sit on.

Once installation was complete it was found that the stability of the piles was adequate and cross bracing was not required on this occasion.

 

Customer’s feedback-

 A brilliant system which I wouldn’t hesitate to use in the future

Maurice Fishlock

 

*the 60RL is a light duty of the 60R, a cheaper option for low loadings, the difference between the 60R and 60RL is the tube thickness.

Easter Glentore Wind Farm

Easter Glentore is a wind farm situated between Glasgow and Edinburgh. This project entailed the jacking of two substation transformer units back to their original level.

The very poor ground was a mixture of soft undisturbed peat along with 5.5m of infilled stone that had over a period settled and caused the substation units to subside on one side. The movement of these units, both weighing in at around 12t was putting the underground electricity cables which are fed from the wind turbine at risk of damage.

ABC Anchors were asked to install screw piles along the subsiding edge of both substation units and bring them back to level using underpinning jacking brackets.The project needed careful planning due to the potential damage to the underground cables during the pile installation and the cost of having the wind turbine shut down for longer than necessary.

As always with the underpinning process, careful excavation to expose the footings was the first operation. The units were both set on 300mm thick concrete slabs so once the underside of these had been exposed localised pockets could be cleared away under the edge of the slab to allow for the jacking plates. The piles could then be installed using the ABC 500X torque head mounted on a 5t excavator. 4 piles were used on the smaller unit and 7 and the larger one. All the piles needed to be installed to 4kNm of torque which meant they were 6m deep in order to penetrate the hard undisturbed layer which started at 5.5m.

Once all the piles were in place the jacking brackets could be fitted and the jacking up process could begin. Care is always taken during this process to ensure the structure is loaded equally and no damage is incurred.

40kN hydraulic jacks were used on each pile making the leveling of the units a simple operation. With the piles all preloaded equally and the units back to level the jacking brackets could be locked in place using the M16 threaded bars and the jacks removed.

Finally the excavated soil is replaced with a type 1 scalpings and compacted to ensure there is no movement between the piles and the foundation.

Customer Comments

This was our first time using a screw piling system and I would highly recommend it, I would give the guys a 10/10!

Darren Hendry

CLM – Ferry Bridge

Ferry Bridge is an historic suspension bridge in Burton on Trent which was in need of refurbishment work during October 2015.
In order to carry out the repairs to the bridge a scaffolding system was required to be set up to allow access for the contractors. The Scaffold system would rely on the screw piles to act as the full support. The loading on the anchors would be both the weight of the system and also the side loadings from the river current and any debris floating down stream.

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Conservatory Underpinning – Cooke Brothers

The conservatory had dropped approximately 60mm and opened up the brickwork. When I installed the Screw-Piles and used the underpinning bracket and jacks, I was able to lift the complete structure back to original height.

I used my own Micro Digger as a powerpack for the 400H driver head.

The gap in the brickwork was closed, windows and doors that were jammed out of alignment all now work perfectly.

I was very happy with the serviced provided by ABC Anchors, they were very accommodating with shipping the equipment over to me in northern Ireland. I would recommend the screw pile system to anyone with similar foundation issues. it worked very well.

Allistair Cooke

Scaffolding – Dyrham Park Roof Repair

When the 150 year old leaking roof of the 17th century Dyrham Park House needed to be repaired, the first step was to cover the whole house in a temporary scaffolding cover to keep the elements at bay.

Investigation showed that the ground around the house could not support the load imposed by the scaffolding.

ABC Anchors were asked by the main contractor Ken Biggs Construction to install over 100 screw piles to absorb the tensile and compressive forces from the complex structure, which weighs well over 200 tonnes.

With a 3 tonne mini digger, installation proceeded quickly, despite the need to work around the delicate building and paved garden structures. Some areas were inaccessible using the 3t digger. It was therefore only possible to install the piles using the ABC 400H hand held torque head.

The screw pile solution was proposed by Integral Engineering Design who worked with the National Trust to bring the project to fruition.

One feature that is quite unusual on this structure is the public access viewing platform, from May 2015 they will have a fully accessible scaffolding tower and lift, with a walkway where you can see the conservation in action and enjoy the views over the gardens.

Blue forest – Belton House Adventure Playground Bridge and Walkway.

This project involved installing foundations for a wooden footbridge and wooden walkway in an area that was very difficult to access with plant machinery and was protected because of listed ruins in the area. The area was also extremely boggy and could only be accessed for a short period between the wet seasons.

All these restrictions meant that the majority of the foundations would have to be installed by hand and all the equipment would have to be brought to site manually.

It was decided that this project could be undertaken using our 60R piles and installing them with the 400H hand held torque head.

For the bridge abutments we installed 6 screw piles at either end onto which a reinforced concrete slab was poured. The screw piles had to be installed to 5m deep to ensure they were in good quality stable ground. Great care had to be taken not to damage any tree roots in the top 1-2m of soil.

The boardwalk piles proved to be even more of a challenge due to the pile positions being in a partially flooded area of natural bog. The only access was via a temporary wooden sleeper bridge which was only floating on the saturated land.

One row of piles was 4m to the side of the access bridge which made it impossible to reach using the 400H hand held unit as before.

It was decided to use a 3t mini digger to install these 12 piles but it was touch and go whether or not the temporary bridge would take the weight of the 3t machine. Careful manoeuvring and a skilled driver proved that it would be possible to install the piles in this way.

Additional sleepers had to be placed into the bog to allow the digger to reach out the 4m to the pile position and once the pile tip was installed into good ground the excavator could then use the pile for support.

The 12 piles were all installed to 6m deep before adequate torque was reached.

This challenging installation proved a great success as the 12 piles now form the base of a spectacular wooden walkway over an area of natural marshland.