Read about the schemes shortlisted in the UK Project with a Geotechnical Value of up to £1M category for the 2016 GE Awards
This category celebrates ground engineering schemes with a geotechnical contract value of up to £1M. Each of the finalists were asked to demonstrate innovative design, value engineering, involvement with project stakeholder and community, and efficient delivery. The judges also expect entrants to provide evidence of exceptional measures that were taken to ensure the project was delivered above the expected standard.
Aecom: Great Western Route Modernisation, Box Tunnel track lowering
Track levels in Box Tunnel needed to be lowered to create space for overhead line electrification equipment and Aecom was tasked with assessing the stability of the 180 year old tunnel and developing a design to lower the track. Aecom undertook ground investigation and 3D ground modelling to develop the design. The company also procured specialist monitoring equipment to ensure the work was carried out without compromising the overall tunnel structure.
Amey and Electrokinetic: English Bicknor slope remediation for Gloucestershire County Council
Ground movement in 2014 at English Bicknor affected an 80m section of road and closure led to a 12km diversion. Amey advised Gloucestershire County Council that the most cost effective and sustainable remediation approach to stabilise the slope was to electrokinetic treatment.
Electrokinetics worked with Amey to develop a design to install electrodes into the failed ground through which an electrical current was applied for up to eight weeks consolidate the failed material. At the end of the work the electrodes were converted to soil nails.
Ash Group and Geotechnics: Access road construction, Cambrian Quarry, Mold, North Wales
An abandoned quarry and adjacent workings left an ugly scar within the picturesque Clwydian hills, together with dangerously unstable rock faces and potential hazards to residents and visitors. Geotechnics worked with Ash Group to develop a new access road and stabilise the rock faces to allow the former quarry to be used for the disposal of inert waste, which would allow the site to eventually be returned to agricultural use. Geotechnics advised on realignment of the road to save costs and remove the need to construct a large retaining wall.
Bam Ritchies: RNLI St Davids Lifeboat Station, Pembrokeshire
Construction of a new lifeboat house was needed at St Davids to house the new Tamar class boat but the location of the site at the foot of an exposed cliff called for Bam Ritchies to undertake some complex geotechnics work for main contractor Bam Nuttall.
The work included cliff stabilisation to allow rock socketed piles for the new boat house and slipway to be constructed. The piles had to be undertaken using a mix of land-based and over water techniques, suing some of the largest down the hole hammer drilling equipment in Europe, to cope with the intertidal nature of the site. Limited space and the potential for weather disruption meant the work had to be carefully planned.
BBMV joint venture: Crossrail contract C512 Whitechapel
Crossrail’s Whitechapel Station interfaces between existing East London Line (ELL) and London Underground lines and involves construction of five new lift shafts including the west lift lobby to give step-free access to ELL. Sequencing of the construction had to be carefully planned as the shaft is between platforms and located 1.5m from the base of a tower crane being used for other parts of the station work. The Nordlund pile analysis method was used to approximate a linear stress distribution on the face of the pile and the horizontal component that could be applied to the shaft piles. The excavation support was also modelled in 3D Autodesk Robot to validate anticipated movement.
Soil Engineering Geoservices: Shieldhall Strategic Tunnel – Jura Street
Former coal mine working around the launch chamber for the tunnel boring machine (TBM) on Scottish Water’s 5km long Shieldhall Tunnel called for grouting work to be undertaken to minimise the risk to the tunnelling phase. Soil Engineering worked closely with main contractors Vinci Construction Grands Project and Costain to undertake the work in the residential setting of Jura Street to reduce the impact on local residents while keeping the work on programme. The work involved both consolidation grouting of the mine workings and permeation grouting around the TBM launch chamber.
Spie Fondations UK and Byrne Looby: Building 4 at Jersey International Finance Centre, St Helier
Development of a former car park, which was built in front of an historic sea wall on reclaimed land, as the site new office building presented some challenges to the basement construction. Foundation contractor Spie and Byrne Looby developed an alternative the planned contiguous piled wall which would not have called for breaking out of the buried wall structure. The alternative used alternating CFA piles founded on the buried wall and rotary percussive micropiles cored through the wall to socket into the underlying bedrock to for the retaining structure for the basement excavation.
United Utilities, GHD Livigunn and Askam Civil Engineering: Earnsdale Impounding Reservoir improvement works
The earthfill embankment dam on the Earnsdale Reservoir was built over 150 years ago and needed to be stabilised to prevent failure. United Utilities proposed a toe berm to provide stability but complex ground conditions around the toe led GHD Livigunn and Askam Civil Engineering to develop a design using a weighted filter on the downstream face of the embankment and a berm formed with galvanised steel mesh and dry stones to provide support to the toe of the embankment. The team developed an observational method approach to deal with the risk of ground movement during the construction phase.