Author: odollie

Book your CPT seminar

By ,

A great way for you and your team to find out more about CPT and the benefits it can bring to your projects is by booking a Lankelma CPT seminar.

The seminar, which can be held at your office over breakfast or lunch (provided by us) will take about an hour. It can be tailored to your specific needs and experience of CPT, covering anything from first principles, to specific applications such as railways, contaminated land and nearshore and marine projects.

Find out how CPT can:

  • Deliver high quality, repeatable results, in real time
  • Measure in situ stress conditions and soil shear strength
  • Help refine ground models
  • Give confidence in conventional borehole and testing results
  • Provide data that can be used directly in geotechnical design.

To book, and to discuss your specific requirements, please contact us using the online form.

  Category: Company News
  Comments: Comments Off on Book your CPT seminar
  Other posts by

Tackling nearshore challenges

By ,

Eric Zon, Lankelma Managing Director.

Meeting the challenges of nearshore geotechnical investigations requires specialist input, not simply a transfer of land-based techniques to the marine environment.

Like any engineering project, those being built in nearshore environments (in water depths of less than 20m) – such as ports, pipelines, cables and coastal defences – rely on good quality geotechnical and sample data to provide ground information for initial project planning and consent applications, right through to detailed engineering and design.

However, consultants involved in nearshore projects often look to the onshore geotechnical sector to acquire data. This can result in site investigations using effectively “land-based” techniques on the beach and foreshore, both challenging tidal environments, and over water, typically from jack-up platforms.

This may not always be cost-effective or appropriate and can result in higher investigation costs and increased engineering risk.

Unique challenges

Nearshore investigations have their own set of challenges, not least the cost: mobilisation can be up to 20 times more than land-based investigations. A full compliment of jack-up platform, drill and CPT rig, welfare units, inflatable boat and crane can take up to 11 low loaders to mobilise and require a 100 tonne crane to put it all together. Operations can cost ten times as much per metre as land work, due to the high cost of the marine plant involved and the lower productivity.

And, while marine investigations normally run 24 hours-a-day in the nearshore (on beaches and in ports and harbours), teams also have to deal with local residents, so working hours can be restricted. This means expensive equipment, such as jack-up barges (which are normally charged out per 24 hours) can potentially only be used for 10 or 12 hours a day, increasing the cost per position further.

Even with 24-hour working, productivity can be half that of onshore work, due to the logistics of moving between positions; working with the tides and marine traffic and dealing with the weather. Using techniques such as cone penetration testing can, on the other hand, significantly speed-up data collection.

Weather is a particular challenge. Weather down-time on land is negligible but in the marine environment it is not only the movement of the jack-up platform that can be restricted by bad weather but it can also cause issues for getting staff on- and off-board, which might mean abandoning the platform before bad weather hits.

Investigations also need to be carried out in conjunction with environmental and habitat assessments; unexploded ordnance studies; geophysical and hydrographic surveys; ground modelling; volume assessments and foundation design. This integrated approach typically improves data quality and cost-effectiveness significantly.

There are a number techniques for acquiring geotechnical, geochemical or geological data in nearshore environments other than from fixed platforms, from seabed penetrometer systems (for insitu CPT); to small mini-vibrocores for use on local vessels; standard and heavy duty vibrocorers; underwater rock drills, grab samplers and seabed probes. This marine equipment can also be deployed from a crane on a quayside or from the shoreline, saving costs, but is then often only suitable for shallower investigations.

When operated from nearshore survey vessels and platforms, these systems will result in significant time savings, compared with land-based systems mounted on a jack-up or barge.

For example, a seabed penetrometer system or vibrocore rig can be mounted on a small multi-cat type vessel. These flat-bottomed craft have a shallow draft, making them ideal for very shallow water. And, as seabed-deployed geotechnical equipment is usually not on the seabed for more than 30 minutes, it is possible to access intertidal areas on a rising tide.

Employing specialist marine techniques for nearshore investigations should result in improved and optimised data acquisition for projects. When processed and modelled by engineers specialising in marine geotechnics and geology, this approach will help ensure surveys fully meet the project objectives, and ensure they are completed in a safe, timely and cost-effective way.

We’re here to help

We are always looking at new ways to help clients and partners, so please get in touch if you want to discuss how we can work together to share ideas and develop solutions to your geotechnical challenges.

  Category: Company News
  Comments: Comments Off on Tackling nearshore challenges
  Other posts by

CPT: The ideal solution for rail ground investigations

By ,

Chris Dimelow, Lankelma General Manager.

Ground investigations on the railway are often challenging, with tight timescales – mainly during night-time and weekend possessions – on sites with difficult access and tight working space. Then there is the challenge of data quality and timely access to results.

In the past, most rail investigations have relied upon dynamic probing and window sampling over conventional boreholes. However, while these techniques are fast and relatively simple, they are limited in the subsurface materials they can investigate; often they cannot reach the required depths and the data they provide is of limited use.

 

 

 

 

 

 

CPT is ideal for rail investigations because it is fast, quiet and clean, producing no spoil, and can achieve deeper penetration than dynamic probing. The high quality data it produces can be used to determine soil parameters including soil type, soil density, insitu stress conditions and shear strength for use in geotechnical design. For instance, CPT results can be used directly for piled foundation design in sands and gravels.

UK12 - Rail Truck 

You can find out more by reading our introduction to CPT blog.

A major advantage for railway investigations is CPT’s speed. Typically, a 15m deep CPT takes about 40 minutes, so between four and five tests can be carried out in a six hour night-time possession, including the time for getting on and off site (depending on how far test positions are from the site access point, of course).

CPT results are also available in real time, which allows engineers to take decisions on site during the investigation. This is particularly useful when identifying the best locations for further testing, sampling and monitoring. This is a key consideration, as detection of potential problems is of paramount importance on the railway.

On-track CPT plant

As the use of CPT in railway investigations has grown, Lankelma has developed on-track plant and equipment designed specifically for investigations in the four main rail environments: trackbed, embankments, tunnels and stations.

All of this kit can be used with the full range of standard and specialist cones, can take samples and be used to install instrumentation. Provided there is sufficient reaction force and a power supply, CPTs can be carried out almost anywhere.

For example, in trackbed investigations, CPT can be used to measure the thickness and quality of the ballast and sub-grade and can be used in conjunction with Ground Penetrating Radar to help correlate data.

Embankment investigations

Where CPT comes into its own, however, is on embankment investigations because embankment materials – clay, sand and gravel – are particularly suitable for CPT. This has resulted in the development of highly mobile, lightweight plant able to test through the 4-foot ballast on an embankment; on the embankment or cutting slope itself; and at the toe.

Our crawler rigs, for example, can cope with embankment slopes of up to 40°and carry out tests on slope angles of up to 15°. They can perform both vertical and inclined CPTs through embankments and some can screw themselves into the ground for additional reaction force. Mini-crawlers can also travel up and down the cess with ease and, if needed, are small enough to work in positions with restricted height. Typically, once set up on position, a mini-crawler can carry out a 10m test in about 30-40 minutes.

Where high reaction forces are needed (up to 10t), our rail excavator-mounted CPT rig may be the answer. Mounted on the excavator arm, this runs off the machine’s hydraulic and electrical systems, so is self contained, with the added advantage that testing can be carried out up to 6m from the track. It can also be used in tunnels, pushing horizontally and even vertically downward using a swivel hitch.

 

Investigations in tunnels and stations

Investigations in tunnels can be a challenge, so we have developed lightweight hand-mobilised CPT rams for tight access positions. These are bolted into position on the tunnel walls to gain reaction and can test in multiple orientations as a result. The same equipment, which is electrically powered, and therefore quiet, is suitable for testing within open stations or at the end of platforms.

 

 

 

 

 

 

Lankelma’s road-rail CPT unit

 

Rail Unit

One of the biggest innovations in rail-site investigation in recent years has been our road-rail CPT unit. Arriving by road, the truck has a central turntable mechanism which lifts it into the air and allows it to be rotated through 360°, allowing it to gain access to rail tracks at most access points. It can travel easily between positions, can be driven backward and forward at the same speed and is self-contained, carrying two operators to position with all the testing equipment.

CPT is an ideal choice for rail site investigations, as it is fast, safe and technically superior to conventional investigation techniques. Producing minimal soil disturbance and spoil, CPT can characterise subsurface materials insitu, produce continuous profiles immediately and its high quality repeatable results can be transferred digitally.

We’re here to help

We are always looking at new ways to help clients and partners, so please get in touch if you want to discuss how we can work together to share ideas and develop solutions to your geotechnical challenges.

  Category: Company News
  Comments: Comments Off on CPT: The ideal solution for rail ground investigations
  Other posts by

What is cone penetration testing?

By ,

Joe Hobbs, Lankelma Technical Manager.

The cone penetration test (CPT) involves pushing a cone penetrometer – the cone – on the end of a series of rods, vertically into the ground at a constant rate of 20mm per second, to depths of up to 100m.

The forces on the cone and the friction sleeve above are measured every 20mm to obtain detailed information about the soil conditions (CPT is suitable for a range of soil but cannot be used in rock).

Results are available almost instantly and can be used to determine soil parameters including soil type, soil density, insitu stress conditions and shear strength for use in geotechnical design. For instance, CPT results can be used directly for piled foundation design in sands and gravels.

 

 

The most common cones used are the standard cone and the piezocone, the latter measuring porewater pressure. You can see our full range here. A number of special cones are also available that can be run concurrently with the standard cone test to cope with different geological environments, to evaluate a huge range of soil parameters, as well as to take samples and install geotechnical instrumentation.

 

The advantages of CPT

  • Greater delineation of strata, as readings taken every 20mm
  • Repeatable, high quality and reliable results available in real time
  • Electronic data transfer means more manageable data handling
  • Test is quiet, produces no vibrations and creates minimal soil disturbance
  • High productivity (up to 150m tested per day)
  • Instant results allow on-site selection of the best locations for sampling, testing and monitoring
  • Huge range of cones for geotechnical investigations, contaminated land studies and unexploded ordnance detection
  • CPT can be used for obtaining high quality samples and installing instrumentation.

To learn more, watch our Introduction to CPT video

We’re here to help

We are always looking at new ways to help clients and partners, so please get in touch if you want to discuss how we can work together to share ideas and develop solutions to your geotechnical challenges.

  Category: Company News
  Comments: Comments Off on What is cone penetration testing?
  Other posts by

Lankelma supports Atlantic rowing team

By ,

We are delighted to be one of the sponsors of a team of rowers taking part in this year’s Talisker Whisky Atlantic Challenge to raise awareness of plastic waste in the ocean.

Starting in December, theOcean 5 team will row 4,800km from the Canary Islands to Antigua. Rowers will each row about 10 hours a day and the team expects to take about 40 days to complete the journey, coping with wind, waves and storms along the way.

The Ocean 5 hope to raise £250K for the Plastic Soup Foundation, a charity that works to reduce the amount of plastic being dumped in the world’s oceans.

This is an issue close to our hearts – Lankelma’s team includes some keen sailors and we strive to reduce the impact of our work on marine environments. This includes preventing any rubbish getting into the sea; using environmentally-friendly products wherever possible and minimising waste from our drilling and testing operations.

  Category: Company News
  Comments: Comments Off on Lankelma supports Atlantic rowing team
  Other posts by

Rapid reporting in Rugby

By ,

Our rapid turnaround of test results gave engineers from consultant Hydrock more time to analyse data on a recent investigation in Coton Park in Rugby. Our tracked rig UK2 carried out 28 piezocone CPTs to a maximum depth of 20m through clays and silts that became very stiff at depth.

Hydrock’s Ciaran Davis said: “We were very pleased with how Lankelma communicated with us, plus we received the preliminary reports the day after testing. Additionally, we found it extremely useful to get the full report and AGS data within three working days after finishing site works, giving us plenty of time for analysis.”

  Category: Company News
  Comments: Comments Off on Rapid reporting in Rugby
  Other posts by

Decontamination in France

By ,

Our steam-pressured decontamination system for cleaning rods before they re-enter the truck kept our site team safe from potential harm on a recent project for Golder Associates in Tavaux, France.

After a rapid mobilisation of our track-truck UK3 from the UK, we carried out seven piezocone CPTs, to between 20m and 30m depth, through chemical tailings at an industrial waste storage facility. We also carried out 91 dissipation tests and two in situ shear vane tests, plus we took 11 Shelby samples that were shipped to the UK for testing.

  Category: Company News
  Comments: Comments Off on Decontamination in France
  Other posts by

Minicrawler ingenuity in south west quarry

By ,

Our team came up with an ingenious, and sustainable, way of coping with a stiff clay layer when testing an embankment in a quarry in the south west.

As well as following the normal procedure of using screw anchors to fix the minicrawler rig to the ground, we fitted a frame either side of the rig allowing two tonnes of quarry sand to be used to provide extra reaction force for the push. This set-up ensured four CPTs could be carried out to a maximum depth of 16.5m. Project Engineer Paul Dimelow said: “This was a speedy and cost-effective method of acquiring data on a site with weight restrictions. The client was excited about using similar techniques on future projects and was dancing around the quarry in delight at the success of the testing!”

  Category: Company News
  Comments: Comments Off on Minicrawler ingenuity in south west quarry
  Other posts by

Verifying soil mixing in Finland

By ,

We have just finished carrying out more than 150 CPTs and insitu shear vane tests to provide an accurate measurement of soil mixing column shear strength in Kittila, Finland. The 18m long columns were being used to raise a mine tailings dam.

Michel Julien, Vice-President, Environment, Agnico Eagle Mines, said: “I would like to take the opportunity to thank Lankelma’s team for its hard work, which has set a new standard in our company. We have collected a lot of very good data and our preliminary interpretation indicates the deep soil mixing has significantly improved the behaviour of the tailings.”

  Category: Company News
  Comments: Comments Off on Verifying soil mixing in Finland
  Other posts by