Ground investigation for HS2 is now underway but there are still hurdles to overcome. Head of ground investigation Jonathan Gammon discusses progress and challenges experienced so far.
Meeting the ground investigation demand for HS2 has been an ongoing concern and the market expected to be overwhelmed following announcement of the framework contractors in January. So far only nine out of 92 work packages have been awarded but head of ground investigation Jonathan Gammon expects the work to ramp up soon.
According to Gammon, there have been a number of challenges around getting work underway on site – one of the main ones being access. Nonetheless, he says that work will come thick and fast for tender in the next few months.
“We have just revisited our strategy,” explains Gammon. “In the early days when we set out the programme for the ground investigation, the driver was the main civils work contracts and the order that they were to be awarded. At the outset there were 23 contracts but over time that has been consolidated.
“Contracts were reduced to 13 and now six or seven. The emphasis was on the order of the work starting with London and getting the tunnelling work started in the early packages, particularly for the Northolt and Bromford tunnels.
“As we’ve learnt more about the situation with regard to access, we have had a long hard look at the situation, reviewed the process and – this is not yet approved internally – but the objective is to place more emphasis on the availability. We will cater for priorities as they are presented by the design team.
“Even with local authorities that we thought were going to be easier to work with there have been challenges and, having awarded the work to the contractors, we were having to stay their hands due to the access challenge.”
IN THE FRAME
The framework is for four years, with a plus one, plus one, so it could extend for up to six years. Gammon says that this fits in nicely with the start of the major civils works, so there will be ground investigation contractors available through the framework should any further investigation be needed at that stage for detailed design work.
The 92 work packages are split between Lot 1 or Lot 2 contract depending on the size and value.
“We wanted to try and capture as much of the market as we could in terms of both large and small contractors, so Lot 1 is for contracts valued at £0.5M to £5M and Lot 2 is for contracts valued at under £0.5M,” says Gammon. “We are trying to keep the contract value shy of £5M and that is a big demand even for a large contractor.”
“The work is exciting as we are going across lots of colours on the geological map and it is the largest ground investigation in the UK by far”
The framework itself is a zero value contract and the work packages will be put out to tender in nine tranches, which the framework contractors have to bid for.
So far nine contracts have been awarded to five of the contractors but not all of the work has started on site yet. “We had some restrictions on site work in the run up to the election, especially near to London,” says Gammon.
At the moment, Soil Engineering Geosciences has started intrusive work near Birmingham, while Fugro is undertaking ground probing radar (GPR) surveys in London to inform the utilities team. Bam Ritchies is soon to start work near Birmingham and WYG will also shortly be working in Birmingham and London. Ian Farmer Associates has also just been awarded work near Birmingham.
“The work amounts to around £50M which is a large proportion of the UK’s ground investigation capacity,” says Gammon. “I believe that the industry capacity was initially valued at £80M but having spoken to more people in the industry I think it is more like £150M once you include the smaller firms.”
HS2 had expected the work to be split 30%, 30, 20 and 20 between years one, two, three and four.
“We had expected a peak of activity this year but the access challenges mean that this will be pushed into 2016,” says Gammon.
“It gives the industry time to adapt and recruit to meet the demand – that’s the upside. We always expected to learn a lot from the first eight packages in terms of the management and work itself and then ramp up dramatically but the increase in work is now likely to be less dramatic.”
Given the evidence still being given to the HS2 select committee, you’d expect protestors and site security to be an issue for the ground investigation but so far this has not been an issue.
“Enquiries in London have more been out of interest and nothing aggressive,” says Gammon. “If the public ask contractors about what they are doing, we have a card they can give them with contact details for HS2 so they can ask questions directly. We have had very few enquiries so far.”
While the access may be an ongoing challenge, the work itself is fairly straightforward except when you look at it from an overall perspective.
“The work is exciting as we are going across lots of colours on the geological map and it is the largest ground investigation in the UK by far,” explains Gammon. “We are covering a lot of country, covering lots of ground conditions with lots of structures.
“Some materials we know a lot about but others we don’t so there is a challenge to get on top of the engineering properties and behaviour.
“We are looking at a whole range of techniques and testing programmes, including a pressure metre version of the cone penetration test. We are also establishing type descriptions and reference boreholes with more detailed description. There is lots of insitu and lab testing planned to really understand the engineering properties.
“It’s less about unusual ground investigation and more about the volume of work – we have 10,000 test locations.”
Some of the site work will be subcontracted by the framework contractors and HS2 is placing the onus on transferring the quality, behaviours and requirements to subcontracted work on the principal contractors.
“We have been encouraging the framework contractors to start developing partners and subcontractor arrangements and establish long-term relationships,” says Gammon. “Ground investigation is an exception within engineering where partnership and joint ventures have become normal practice. Partnerships will make it easier to ensure quality, behaviours and requirements are maintained both on site and in the lab.”
Given the number of samples that will be tested over the next three years, maintaining test standards is clearly a concern. The laboratory proficiency scheme has shown wide variation in the past which could have significant design consequences for HS2. Gammon acknowledges the issue and says that in addition to encouraging the ground investigation contractors to partner with subcontractors, HS2 is also encouraging similar arrangements with laboratories. “In addition to overseeing work on site, HS2’s ground investigation supervision team will also supervise lab work,” he says. “We will be talking to the lab technicians so that they, like everyone on the scheme, understand what their work is contributing to.”
When asked about the biggest challenge still facing the ground investigation phase, Gammon says that it is still access. “All licence applications for access will be out soon, rather than being staggered as originally planned, so we will soon be able to plan the work around access availability more effectively,” he adds.
Nonetheless, HS2 hopes that the project will gain Royal Ascent at the end of 2016 which will ease the access issues for both the London to Birmingham phase as well as the northwards extension. “Royal Ascent will give us rights of access so ground investigation in areas that we see as particularly difficult will be postponed until after that date,” says Gammon.
● Allied Exploration and Geotechnics (Lot 2)
● Bam Ritchies (Lot 1 and 2)
● Environmental Scientifics Group (Lot 1 and 2)
● Fugro Engineering Services (Lot 1 and 2)
● Ian Farmer Assoc (1998) (Lot 2)
● RPS (Lot 2)
● Soil Engineering Geoservices (Lot 1)
● Structural Soils (Lot 1)
● WYG Environment Planning Transport (Lot 2)