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!

Confor 2017 – Register your interest

This September, our sister company Autoguide Equipment are celebrating their 40th anniversary, since being established in 1977! This anniversary is important as testament to many years of success and experience in the landscape construction and agricultural industries. Since the Confor Woodland Show corresponds perfectly, we are celebrating at stand, W47, on the 7th and 8th of September.

ABC Anchors will also be featured on the stand, with a tree friendly screwpile foundation system, recommended by the top arboriculturalists.

Autoguide's range of vibrating post drivers will be demoed at the show. Since it is such a special occasion, we are making a limited edition Midi Postmaster. Rubies are of course the gemstone associated with a 40th anniversary, so look out for this as a theme!

In following with our celebrations, we will be giving away a free ‘ruby’ gift to the first 40 enquiries. This will be on both days, so get in quick to avoid missing out! All you need to do is leave your details with your enquiry. If you’d like to register your interest online to save time on the day, please fill out the contact form below.

To keep updated on our celebrations, check our website regularly and subscribe to our newsletter.

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

We Are On Your Screens!

Save the Dates...

21st September

Dursley Tree House featured on Grand Designs!

Wednesday 21st September 9pm on Channel 4

This project will also be featured in The Sunday Times Homes section on the 18th September and Grand Designs magazine 12th September.

 

 

22nd September

Another to look out for! Woodman’s Treehouse

Thursday 22nd September 8pm on Channel 4

The building of the treehouse was filmed for the first episode of the new series of George Clarke's Amazing Spaces.

ABC Anchors are proud to be involved in these projects as the manufacturer of the piling work needed for the foundations . Dursley Tree House and Woodman’s Tree House are just one example of the solutions ABC Anchors has to offer to most screw pile applications.

Don't miss the opportunity to see our piles in action!

 

 

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

Tree Roots

Foundations near Tree Roots

"Having specified and witnessed the installation of screw piles I consider they must be one of the most tree friendly foundation systems around. Easy to install from low ground pressure machines working on ground protection they can be installed without material impact to roots."

Jago Keen, Keen Consultants

Disadvantages of conventional Concrete Footings around Tree roots

There are many reasons for not using conventional concrete footings near trees:

Trees will cause desiccation of soils in dry weather and subsequent expansion in wet, resulting in soil movement.

Excavating a trench may well cut through critical roots.

The concrete may have a detrimental effect on the tree, and will certainly reduce the flow of oxygen and nutrients to the tree.

Kew Gardens have shown that the top metre of soil is critical to the health of the tree.

Trees inevitably get bigger so foundation design needs to allow for this.

How do Screw Piles get over these issues?

We arrange for the highest Helix to be at least 2.5m below ground where there is no soil movement, and other Helices will be deeper.

The comparatively slender pile shaft may damage a very small portion of the roots, but the Aeration to the soil round the roots may well actually improve tree viability.

An average pile will be around 4m minimum length, so if we assume that the top 1.5 m of shaft is in soil which moves (up or down) the skin friction will be cancelled by that acting on the lower 2.5m, so resulting in no net movement. Pile capacity does not depend on the skin friction on the pile shaft, it rests entirely on the helices.

Generally structures will be designed to be above the ground, so movement of the soil does not affect the building itself.

Screw piles have both Tension and Compression capacities (about 20-25% more in compression) so can resist any uplift.

Each pile is driven to a specified Torque, and hence known capacity, unlike all other foundations which can only be tested after installation.

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.

Temporary Structures

Temporary Structures

Screw piles make excellent temporary foundations, quick and easily to install and just as easy to remove. Being able to offer instant tensions they are perfect for use as temporary staging, bridges, secure site storage, toilet blocks etc. The removal of the screw piles causes very minimal ground disturbance and piles can often be used again.

We have also used screw piles to support high loads from tower cranes, strand jacks and other vehicles requiring temporary proven solid foundations.

These often have cyclic or reversing loadings. The ability of screw piles to resist both tension and compression plus the low impact of installation and removal is usually key to a successful job.

Transport costs are reduced – 1 tonne of screw piles and extensions can provide 80 tonnes (200 tonnes ultimate) holding power.

Examples

Tents up to 600m2 (65000ft2) are quickly and safely erected using screw anchors, developed specially by ABC Anchors. Tension loads up to 200kN (20 tonnes) are easily accommodated, yet the anchors are quickly removed and reused time and again.

The scaffolding for the temporary roof over the house at Dyrham Park required over 100 screw piles resisting both compressive and tension forces. These piles can be removed and reused once the roof has been repaired.

Concert stages, previously secured using concrete, can now be restrained with hand installed lightweight screw piles.

Wind turbines suit screw piles really well as they can be quickly erected and repositioned if required with very little effort.

 

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.