625kN Pile Test – Restricted Access London Site

When configuring suitable screw piles for a project, our Engineers rely heavily on soil properties determined from geotechnical investigation. Often undertaking soil testing using the ABC Anchors soil test probe, or commissioning a full soil investigation (SI) report from a geotechnical engineering firm provides us with sufficient design information. On small projects, use of our soil test probe instead can significantly reduce the cost compared to an SI report and provide similar results for specification purposes.

There are occasions however when pile testing is necessary to confirm our pile specifications.

ABC Anchors was recently contacted by a Client looking to install screw piles for a residential project in close proximity to the Thames in London. From an initial review of the SI it was understood that the site was underlain by a thin layer of dense gravels, however the soil properties below this were not described in the report. Being London based, an area known for weak Clays, and with a site in such close proximity to a river; it was decided that the soil report could not be relied upon alone. As the project required over 50 piles to be installed with design safe working loads of 20 tonnes per pile, it was critical to test the pile under load to confirm that any settlement was within acceptable limits.

ABC Anchors installed an 89R test pile to an installation torque of 25kNm using our Autoguide 2500X torque head mounted on a 3 tonne excavator. Typically excavators between 5-10 tonnes are used to install piles of this size, however as the site access was restricted to a small alleyway only 1.5m wide, a 3 tonne excavator was the only option. It was a testament to our Engineering team’s ingenuity and the skill of our installers that installation torques of this magnitude were achieved using such a low powered machine.

The pile was tested using our recently redesigned ABC Anchors testing equipment and experienced only 2mm of settlement when loaded to the pile’s ultimate load capacity of 62.5 tonnes. The Federation of Piling Specialists suggest that allowable settlement should be no more than 10mm under working loads.

The testing was a complete success and confirmed the suitability of our 89R rock tip pile for the project.

Installation Packages

Package Choices

We can offer several packages for the supply and installation of our screw piles.

We can supply the piles and offer full installation with this you get a full installation pile log with guarantee of work

We can supply the piles and hire out the installation equipment for you to install.

Training courses at our premises or onsite (How to correctly use our equipment to install screw piles)

Onsite guidance


 

Torque Heads

400H
400H

500X / XG
500X / XG

650H
650H

1600X
1600X

2500X / XG
2500X / XG

All our torque heads are manufactured by our sister company Autoguide Equipment and can be either purchased or hired from us. This can be on a daily or weekly basis.

Downloads

ABC Torque Heads

Equipment Hire

Screw Pile Installation Equipment Hire

ABC Anchors offer a range of Autoguide’s screw pile specific torque heads for hire. All torque heads come equipped with torque gauge for driving screw piles to the required installation torque.

Installers for 60R Piles

400H Hand-held Anchor Drive

Our 400H portable anchor installer is available with or without the hydraulic power pack and is ideal for use in confined spaces or areas of limited access. We hire this machine for installing our 60R screw piles, to accommodate loads up to 48kN.

500X / XG Torque Head

We have a range of mounting brackets to attach the 500X to excavators from 1.5 to 6 tonnes. This allows anchor installation at a wide range of angles. When access is not an issue, installation using the 500X instead of our handheld equipment allows our 60R screw piles to accept loads up to 60kN.

400H
400H

500X / XG
500X / XG

Installers for 76R Piles

650H Hand-held Anchor Drive

The 650H portable anchor installer is available with or without the hydraulic power pack and is ideal for use in areas of limited access much like the 400H. This larger handheld machine can accommodate loads up to 73kN with our 76R screw piles.

1600X

The 1600X is the torque head of choice for installing our 76R screw piles, accepting loads up to 180kN. It can be mounted using a range of brackets to excavators from 4 to 7 tonnes.

650H
650H

1600X
1600X

Installers for 89R Piles

2500X

The 2500X is an excavator mounted torque head for use with 89R screw piles. Our largest pile can accept loads up to 250kN and must be installed using an excavator from 4 to 10 tonnes. The torque head is shown here with the Gimbal bracket, which allows installation when head room or the excavator boom arm length is an issue; mounting on the side of the head rather than the top.

2500X / XG
2500X / XG

Soil Test Probe

The soil test probe is used to determine the soil conditions on site where no soil investigation information is available. Torque readings are recorded at 250mm intervals to provide an indication of the properties of the soil. These readings can be easily correlated against SPT value charts to determine the soil type and it’s suitability for accepting screw piles.

As a general rule, screw piles are not designed to penetrate solid bedrock, nor are they able to penetrate through obstructions such as boulders or buried concrete. However most other soil types are acceptable.

Being hand driven or with a high torque battery drill, the data produced allows the engineer to design the most suitable pile configuration for the calculated loads.

On many small projects use of this equipment can result in overall price reduction (especially compared to a full ground investigation), with a high level of confidence in the finished result.

Soil Test Probe
Soil Test Probe