Drilling large diameter boreholes at a brownfield site to install anodes for a cathodic protection system requires a rather eclectic combination of skills.
Working in a tight space, to a detailed specification, we achieved an anode installation through a complex sequence of geological strata. Clean drilling techniques required us to install an environmental seal through surficial gravels and 30m into underlying clay. We then extended the boreholes through 20m of Thanet sands and 10m of flinty chalk. To complete the anode installation we then tremmied sacrificial coke contact media into the borehole’s response zone with the remainder of the boreholes being grouted back to the surface with bentonite.
Our team consisted of drillers, environmental engineers, mud technicians and cathodic protection engineers, all working together on a busy site to ensure the client got the installation required whilst working within the Environment Agency guidelines. The anodes will now ensure the pipelines are protected for the next 100 years.
If you’d like to know more or if you have an installation requiring cathodic protection be installed then please contact Angus Gale – 01296739433
Our Terrier drill rig, Tinky, recently celebrated its sixteenth birthday. In that time it has had 2 new head gaskets, 15 calibrations, 22 oil changes and services, 2 new tyres, 2 new tracks, 1 rebuilt mast frame, 1 new radiator , 1 new weight guard and a new fan. We know that good maintenance is the key to keeping any machine working and we like to think we’ve done our Terrier proud. It has certainly paid us back.
It may be sixteen years old but last week it still managed to dynamically sample 25m of weathered sandstone to 5m depth with SPT tests every metre plus completing an additional four dynamic probes to competent bedrock at 9.5m and installing four gas monitoring wells to 1.5m. All this in two days including a round trip mobilidsation of over 300 miles. Hats off to Tinky.
We are looking for dynamic sampling operatives. If you think you fit the bill then give Angus Gale a call on 01296 739400 or email your CV to Angus Gale.
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.
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.
It’s never good when your business premises are reduced to ash in a raging inferno. But this was just the scenario faced by one of our clients, when their car showr0om and repair workshop has burnt down overnight.
We were on hand the next day, working closely with both the fire brigade and the demolition crew. We were able to obtain the vital geotechnical data necessary to allow design for the new buildings to progress.
Here you can see our Terrier rig taking soil samples and completing in situ standard penetration tests and dynamic probes to depths of up to 15m.
Now the flames have died out, the demolition has been completed and the new structure has been designed. Our client is well on the way to be back in business.
As the rest of the world turns it attention to Hollywood and the Oscars, we’ve been focused on the only marginally less high-profile What House Awards. One of our clients, Q Developments, picked up two awards, one of which was for their development of a former filling station site in Teddington. We’re very proud to be able to say that we played our part in this project for Q Developments, having undertaken the decommissioning and removing the former petroleum installation and the treatment of hydrocarbon and asbestos-related soil contamination prior to the site’s residential redevelopment. Our congratulations to Q Developments on their award.
No-one can say that our workload isn’t varied. Last week one of our drilling crews completed the following schedule:
Monday – Geotechnical investigation including U100 sampling and SPT testing with our Terrier drill rig;
Tuesday – Water well installation using rotary rock roller with our Commachio 205;
Wednesday – Environmental investigation at a filling station using hollow stem augering, again with our Comacchio 205, while a new canopy was being installed;
Thursday and Friday – Deep water well installation using down the hole hammer to penetrate into a limestone aquifer.
We love a bit of variety in life and this week has proved it so. Time for a rest…….next week looks busy………
The combination of restricted head room and a ‘confined space’ presents major obstacles to any site investigation. However, our Terrier rig was able to gain access and complete a geo-environmental investigation in such a space. Its quite amazing where this little rig can get.
Access was through a standard doorway working with an overhead ceiling clearance of
less than 30mm with the machine set up. Precision operation was required to ensure we completed five boreholes, each to 6 metres in depth, with SPTs every metre, all in a safe and efficient manner.
The nature of the confined space meant that exhaust gases from the Terrier’s engine had to be vented to an outside area. We used an extendable sectional exhaust pipe to ensure a safe working environment. But just in case we also carried out carbon monoxide monitoring to ensure our crew’s safety.
Even better, our work was completed without the need to close the car repair workshop we were working in. allowing our client to continue panel bashing, filling and spraying to his hearts content.
We were commissioned to carry out a geotechnical investigation, including rock coring, at a site located just a stone’s throw from the busy harbour of Dover.
Our Commachio 205 and drilling crew were able to produce high quality cores and gain SPT/CPT data from 4 boreholes, each drilled to a depth of 20m below ground level. All completed on time and on budget.
Voids were encountered at various depths fueling rumours of secret smuggling tunnels similar to those we found in Margate last year. Unfortunately the only treasure recovered were metres and metres of chalk. Better luck next time lads!
OK so not exactly Peru, but a very steep, terraced site in the Chilterns.
The extremely tight access didn’t prevent our site team from getting in and completing a comprehensive geotechnical investigation, including soil sampling and dynamic probing to 10m depth. The work was completed on time and on budget, with dynamic probing data issued to the client on a ‘same day’ basis to assist with pile design.