Atkins Tunnelling
The art and science of tunnelling has made great
strides in recent times, resulting in faster progress, reduced costs,
and better identification and management of risks.
However, to benefit from this modern technology, tunnel design and
construction processes must be integrated within the framework of
a skilfully drawn contracting strategy.
This is where Atkins Tunnelling excels. As a dynamic division of Atkins
Global, Atkins Tunnelling specializes in tunnel scheme planning and
assessment; environmental impacts; concept design; value management;
contract strategy; risk assessment and management; and revenue forecasting
and resolution.
Atkins Tunnelling also offers specialist skills in environmental appraisal;
mechanical and electrical engineering; ventilation; noise and vibration;
acoustics; control and communications; aerodynamics and thermodynamics;
safety and reliability; integrated GIS 3-D modelling/visualisation
capability; heritage; refurbishment; and due diligence studies. |
Hard Rock Tunnelling and Caverns
The Cheung Ching tunnels on Hong Kong's Route 3
Expressway comprise 1,500 m-long twin bored rock tunnels and 50 m-long
twin tube cut and cover tunnels, each 17 m-wide by 10 m-high, separated
by a rock pillar of minimum width 13 m. Excavation was through difficult
ground conditions with highly fractured and weathered zones and seams.
Atkins Tunnelling was responsible for the planning, route selection,
detailed design, documentation, and construction supervision of the
tunnels, portals and slopeworks.
The Lai King tunnel on Hong Kong's Lantau and Airport Railway comprises
600 m-long rectangular and D-shaped running tunnels, which interface
with an existing tunnel and station complex, creating cavernous underground
openings. The size of the openings and complexity of the interfaces
necessitated the use of state-of-the-art rock mechanics to engineer
permanent rock reinforcement systems, for which analysis and design
were undertaken by Atkins. |
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The company carried out an independent review of the design of the
700 m-long x 10 m-high Jinyoung tunnels on the Naeseo Expressway in
South Korea, which comprise twin four-lane motorway tunnels with a
span of 20 m and a separation of 20 m, excavated through fractured
hard rock by drill and blast beneath existing twin roadway tunnels.
The 5.5 km-long, two-lane Hvalfjordur road tunnel lies some 40 km
north of Reykjavik, Iceland and crosses a major fjord using drill/blast
in hard rock, with its nadir some 160 m below sea level. Atkins reviewed
the investigation data, designs, specifications and conditions of
contract, and advised on matters such as methods of excavation, support
control, shotcreting, seismic hazard assessment, mechanical and electrical
plant, ventilation and fire hazard. |
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Soft Ground Tunnelling
Atkins were the designers for the 1.8 km-long,
twin bore 8.4 m-diameter Kwai Tsing, Hong Kong rail tunnels excavated
through mixed ground varying from granite to marine muds using an
EPB TBM.
Atkins (in JV with a French consultancy) was appointed independent
project manager of the 50 km-long Channel Tunnel between UK and
France, and also provided experienced professionals for direct project
management.
At the Docklands Light Railway Lewisham Extension bored tunnels,
Atkins provided detailed design services for the twin 5.2 m-diameter,
segmentally-lined slurry TBM-driven Thames crossing, including permanent
works design of the tunnel, combined cross passage and sump, and
selected temporary works.
Cut and Cover Tunnels and Shafts
At the A12 Hackney to M11 Link Road in London,
UK, Atkins Tunnelling undertook the design and construction supervision
of the 300 m-long George Green cut and cover tunnel and approach
ramps.
The Chestfield Tunnel on the A299 Thanet Way in Kent, UK is a twin
cell cut-and cover tunnel 315 m-long, 30 m-wide and 10 m-high, with
each cell containing a two-lane carriageway, and built on London
Clay. Feasibility studies, conceptual design of the foundations,
and detailed analysis of the tunnel were carried out by Atkins Tunnelling.
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Design of the underground station structures on either side of the
tunnelled River Thames crossing on the Lewisham Extension of London's
Docklands Light Railway was undertaken by Atkins Tunnelling. In Greenwich,
the Cutty Sark station structure was 60 m-long, 25 m-wide and 22.5
m-deep, and was constructed top-down with temporary and permanent
propping at five levels between diaphragm walls.
For cable diversion at Pepper Hill, Kent, UK, four tunnel access shafts
were sunk up to 26 m depth through river deposits and soft water-bearing
chalks with flints by the hydraulic caisson method.
In Blackpool, UK, two underground water storage tanks were designed
by Atkins, each 36 m-diameter and 40 m-deep. |
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Geotechnical Investigations and Interpretation
Atkins Tunnelling undertook a comprehensive site investigation for
the Cheung Ching project in Hong Kong, including the drilling of
two horizontal boreholes of lengths 500 m and 1,000 m, in-situ stress
measurements by means of hydraulic fracturing, high-resolution seismic
refraction surveying, trial blasting in boreholes, and rock machineability
testing.
The 1.9 km-long Hindhead tunnel in UK will pass through a sequence
of inter-bedded, weakly cemented mud/sandstone and sand/clay layers
of the Hythe Beds close to the groundwater table. Atkins is acting
as the Employers Agent for Highways Agency on this Early Contractor
Involvement, Design and Build Contract, and this includes the role
of Geotechnical Adviser.
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Atkins carried out settlement damage assessment along a section of
the Channel Tunnel Rail Link through London, UK, in which settlements
were predicted from anticipated tunnelling face losses, and buildings
along the route were characterized and analyzed to assess the potential
for building damage.
At Athens Metro, following a series of collapses, Atkins provided
independent advice on geological risk and implications for buildings
adjoining the 9.5 m-diameter TBM tunnels. |
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Inspection and Maintenance
Atkins carried out a due diligence study of the
1930s-built Detroit to Windsor tunnel, linking the US to Canada,
for prospective senior equity partners, forecasting costs and risks
associated with the operation of the tunnel to 2020.
A condition survey was undertaken on tunnels along the highway from
Matulji to Cerovlje in Croatia, covering the primary tunnel support
during construction, the secondary lining, waterproofing and mechanical,
electrical and safety equipment.
Atkins has carried out work on a number of sewers in UK, entailing
desk studies of historical and geological information, inspections
of linings, and remediation specification.
Pipe Jacking,
Thrust Boring and Directional Drilling
Atkins were the designers of a project to install a subsea cable
up to 96 m below sea level in curved steel-lined HDD holes of 400
mm-diameter, up to 1,250 m-long, between Lantau Island, Sham Tseng
and Ma Wan in Hong Kong. There were highly fractured fault zones
in the middle of both crossings.
At East Kowloon, Atkins provided design and construction supervision
of a sewer renewal project which included 100 m of 2 m-diameter
thrust boring at a depth of 8-10 m, using a Komatsu semi slurry
shield thrust boring machine to minimize ground disturbance.
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