How Safe is Safe?

Well, in our case the answer is very safe indeed. We’ve just completed our annual HSE audit, carried out by an independent auditor on our clients’ behalf, and scored a record 93%.

The auditors praised PrismERP, the IT system we have developed over the last decade for both managing HSE and integrating it into every aspect of our operations. With further upgrades to PrismERP planned for the coming year, we are determined to get an even higher score next time round.

PrismERP is commercially available. If you’d like to know more about how it might help your organisation please contact Duncan Eastland.

Airplanes Stopped Play

Another post discussing the joys of working at a busy airport. This time we were asked to advise on the allowable bearing capacity for a foundation to be installed at 2m depth, without either excavating a trial pit of drilling a borehole.

We opted to carry out a series of dynamic probes, using our lightweight terrier drill rig, along the line of excavation, using the data to calculate an equivalent SPT ‘N’value and thence an allowable bearing capacity. We were able to provide our client with results in real time, ensuuring there were no delays to the construction programme.

What Did You Do Last Night?

Night Working

Maybe we are cynical but we usually reckon we can rely on the weather to be cold and raining, or even snowing, anytime we are asked to carry out sitework at night. So it made a pleasant change to find ourselves at the end of Runway 27R at Heathrow on a warm summer’s night last week. As a Heathrow Approved Contractor we’d been asked to carry out some urgent groundwater assessment work and because our staff and vehicles hold ‘access all areas’ passes for Heathrow, we were able to be on site quickly and with the minimum of fuss.

For more information regarding our site investigation and remediation capabilities at airports, please contact James Skinner – 01296 739411

Chilling Out at Heathrow

Terminal Four at Night

Working ‘airside’ at Heathrow Airport is always a challenge, but when our client contacted us requesting plate bearing testing of the ground prior to them lifting a new chiller refrigeration unit using a mobile crane at Terminal Four we were happy to help.

The only kind of chilling our engineer enjoyed was the cool breeze while he worked through the night to ensure our testing was completed safely, on time and on budget, allowing the aircraft stand to open in time for the first plane arrival.

Pile Probing

Pile Probing – London

We were contacted by one of our regular clients with an urgent request to carry out pile probing at one of their sites in London. We were able to be on site the next day, using our Geoprobe rig to clear 55 pile locations to a depth of 4m, all before 3pm. To make matters even better, the sun shone all day.

For more information about our pile probing service please contact Duncan Eastland – 01296 739431

Contract Value: <£2k

 

Why You Should Be Using A Qualified Driller

Drilling has tradionally been pretty poorly regulated. Light cable percussion rigs (more commonly known as shell and auger rigs) still dominate the UK drilling market. They are crude, simple to operate and provide low quality samples but they live on because they are relatively cheap.

One reason they are cheap is that their operators are unqualified. Drilling has been seen as a job not a career. But lack of proper training has led to a woeful safety record; it is rare to see a 40-something shell and auger driller who still has all his fingers intact.

The British Drilling Association (BDA) has been working hard for some time now to encourage clients and consultants to require drillers working for them to hold a professional qualification – in this case an NVQ in Land Drilling. All our drillers hold this qualification. Our latest trainee, Alex, completed his NVQ this week.

If you’d like to know that your drilling requirement is going to be fulfilled safely and professionally then we’d be love to talk to you. Please contact Angus Gale (Tel: 07748 358304) for more information.

Draining Away

Soakway Test Pit

The pressure to building new housing seems to be constantly in the news these days. Developers working to meet this demand are increasingly finding that they are required to find sustainable methods for disposing of the rainwater from roofs and paved areas. The days when this could just be discharged to the municipal sewer are long gone. Instead, wherever possible, the water must be disposed of into the ground via soakaways or other similar ‘infiltration features’.

Designing these requires careful measurement of soil permeability. We offer a comprehensive range of testing methods, from hand-dug percolation tests for Sustainable Drainage Systems (SUDS – NHBC Chapter 5.3) to machine-dug test pits for full scale soakaway tests (BRE 365). If site access is limited we can even carry out the requisite testing in boreholes drilled as part of our geotechnical/environmental investigation of the site.

For more information please contact Steven Partridge – 01296 739413

 

When is an SPT not an SPT?

SPT Calibration - 2
SPT Hammer Calibration

The answer is when it’s not calibrated.

The Standard Penetration Test, or SPT, has been the mainstay of geotechnical site investigations in the UK for decades. The test is simple, quick and cheap and it’s particularly suited to the light cable percussion drill rigs that are so widely used in the UK.

What isn’t generally appreciated is that even a low tech test such as this requires proper calibration in order to yield consistent, reliable results. In fact Eurocode 7 requires the SPT hammer to be calibrated annually. Unfortunately very few drilling contractors bother to do this and, in our experience, few consultants know that they should be asking for it. Given that results from out of spec hammers can vary by as much as 50%, we think this is something that should be given more attention.

We’ve put our money where our mouth is and now all our SPT hammers are correctly calibrated and all our drill rigs come with up to date LEAA inspection certificates. If you’d like to know more about our drilling capabilities please contact Angus Gale – 01296 739433.

Bulldog Spirit?

Bulldog SpiritWe are accustomed to working for the big hitters of modern industry. However, today we were handed the opportunity of working around one of the big hitters from history. This WWII machine gun bunker holds listed status, and rightly so. It’s one of 18,000 built, around the coastal areas of the UK during Churchill’s defence against Operation Sea Lion.
Our plucky little rig was able to negotiate perimeter fencing, dense undergrowth, steep inclines, tank traps and machine gun bunkers just to get on site. It all sounds more “Band of Brothers” than “geotechnical site investigation”. In all 28m of dynamic windowless sampling with SPTs (and 2″installs) plus 80m of dynamic probing were effortless completed.

Now that’s the spirit…………..

When Horizontal Just Won’t Do

Anode Installation
Anode Installation

A prominent pipeline client came to us with a problem. A ‘positive’ problem that is. A section of their pipeline runs underground next to a railway line. The railway’s overhead high voltage power lines were causing an amplified positive electrode potential in the ground, which in turn was leading to increased corrosion of their pipeline. In these cases, cathodic protection is the usual solution.

A typical cathodic protection system would comprise a series of shallow earthing rods installed at regular intervals along the pipeline. However, this requires access for maintenance in the future to the entire pipeline. But these pipelines run for hundreds of miles through agricultural land, some of which is only accessible during certain periods of the year. The solution was to design a single anode string capable of achieving the required negative electrode potential in a vertical design. Thus saving on space, maintenance and cost

The client’s senior cathodic protection engineer approached us to see if we could drill a 75m deep borehole and undertake the (negative) anode installation. We took the challenge and set about devising a safe method for installing a multi core anode string weighing more than 300kg! The borehole was installed through 18m of gravel into underlying mudstone. Just to complicate matters further, our environmental appraisal identified a potential risk of penetrating into a sandstone aquifer beneath the mudstone. To mitigate these risks and achieve the required potential we had to install a vent pipe to the base of the borehole, a tonne of coke, gravel and a bentonite seal at the top of the mudstone to ensure the underlying aquifer was protected.

Exactly how we did all this is our secret but needless to say it involved a large rig, and unusually for us, a lot of “negativity” ………….But happy pipeline equals happy client – now that’s positive.