High Speed 2 (HS2) is boosting rail connectivity in the UK with a state-of-the-art, high speed link being delivered in two phases. A brand new line from London to the West Midlands in phase one, planned to be followed by new rail links with Manchester and Leeds as part of phase two, will significantly increase capacity and reduce journey times through the heart of the country.
Site investigations (SI) for phase one are being undertaken to demanding standards. They are providing vital ground engineering and design data for the construction of bridges, tunnels, cuttings and four new stations, as well as 140 linear miles of rail carrying trains at up to 250 mph.
Fugro was one of nine contractors selected for the phase one ground investigation framework announced in January 2015.
Leveraging its international resources, Fugro has been able to quickly mobilise experienced and skilled personnel, together with a versatile range of equipment, to undertake the challenging site investigations. This has entailed not only intensive programmes of geotechnical and geophysical site work, but also high volumes of sample analysis, testing and data processing to help keep the client on track with design and construction planning.
The logistical and technical challenges presented by the scale of the project have stretched the capacity of the UK industry. Fugro’s ability to respond and provide in-house resources and technical expertise from across the Fugro group has enabled us to meet the high expectations of HS2, providing high quality data to further the design of the project as it moves towards the construction stage.
Fugro HS2 contracts so far
The Ruislip North West contract, awarded November 2016, comprised a wide range of SI activities along a 2.4 km section north of London. This has included rotary and cable percussion boreholes to depths of up to 40 metres, wireline logging, seismic cone penetration tests, trial pits, a radiological survey, and laboratory testing.
Fugro has ongoing contracts for the Central London section of the route which include an extensive utilities survey and full range of geotechnical investigations.
Fugro is undertaking rotary core and cable percussion boring, downhole wireline logging, cone penetration testing (CPT), and in situ and laboratory testing. Pressuremeter testing has also been carried out on a number of boreholes.
The intensive schedule of work has been all the more challenging in London’s congested urban environment. Clinical planning and efficient deployment of resources has been crucial in overcoming constraints on access and limited periods of access.
The utilities survey has entailed the scanning of ground penetrating radar (GPR) data and electromagnetic sensing to identify and map underground services across an expansive area, from residential streets to busy roads and across London Underground infrastructure.
With space and access time at a premium, hand excavations have been employed to help target and confirm positions for boreholes to extract ground engineering data. Fugro has been taking full cores and producing onsite detailed geotechnical engineering logs of recovered material for expedient reporting to the HS2 design team.
Fugro’s contract at Great Ufton, completed in October 2016, involved a similar range of ground investigation activities.
However, the geotechnical work has relied on a bigger fleet of equipment to cover a larger area. At its busiest, the borehole programme employed two cable percussive rigs, five rotary coring units and a team of up to 12 geotechnical engineers.
HS2 is demonstrating Fugro’s extensive capabilities to provide a full range of geotechnical and geophysical investigation services to the scale, quality and programming demands of one of Europe’s largest rail projects.
At a time of high demand for geotechnical services but a shortage of skills in the UK, the depth and integration of Fugro’s global resources and logistical mobility have truly come into their own. This includes meeting high levels of technical competence, quality management, and operational accreditation, in addition to onerous insurance, liability and associated contractual considerations.
While technically demanding, a huge challenge is the sheer volume and logistical complexity of the ground investigations.
Fugro has shown that it is well equipped to respond and mobilise the required resources and people, including in-house skills from its global offices. Investment has been made in new equipment, while some tasks are relying on specialised technology. Some of the engineering tests for HS2 are being run on a small strain testing system at Fugro’s state-of-the-art soils testing laboratory in Wallingford (UK), one of just a handful of UK laboratories with this facility.