GE Regional Round-ups Central & South West May 2015 Water, Ground & Environment compiled for internal use only

A36 Remedial Works at Claverton Ground Engineering’s design for remedial works on the A36 at Claverton is currently being constructed for Highways England. A three mile stretch of the A36 Trunk Road, near the city of Bath, is subject to a total closure in order to construct the works. This section of road, part of a primary highway route linking Southampton to the city of Bath, forms a critical part of Highways England’s network but has been exhibiting signs of failure since Remedial works were necessary to ensure long term performance of the carriageway The £2.3million scheme comprises a 238m long bored pile wall, separated into 17 sections due to the local curvatures of the highway alignment. A total of 204 No. 600mm diameter piles are being installed at 1.2m centres to a depth of 13.5m. The defective section of carriageway is situated on sidelong ground within the renowned Avon River Valley, famed for the occurrence of ‘Foundered Strata’. Desk study and ground investigation proved the site to overlie particularly challenging and troublesome Landslip Deposits, underlain by the Bridport Sand Formation. The objective of the works is to extend the life of the carriageway by isolating it from the slope which has been subject to movement caused by the landslip complex. The design was undertaken by our Bristol team as part of Atkins’ framework agreement with Skanksa, who maintain Highway England’s Area 2. For further information please call Louisa McAra, Elizabeth Simmonds or Jon Esser.

HS2 Earthworks – Setting the Standard Birmingham Our Birmingham team has been drafting the Technical Standard that will control earthworks design of the embankments and cuttings for the proposed High Speed Rail link between Birmingham and London (HS2). The standard includes performance criteria developed in collaboration with researchers at the Atkins sponsored Centre of Excellence for High Speed Rail at Heriot Watt University, which was set up to address the specific issues resulting from running trains at the high speeds envisaged for the project. The standard was delivered to the Client, HS2 Limited, at the end of March and is currently under peer review in advance of being finalised later this month and incorporated into the Employer’s Requirements for the project. We have now won a further commission over the next three months to investigate the potential magnitude of heave in the base of deep cuttings and its impact on the construction programme. This is being carried out in Birmingham using Plaxis 2D. This findings from this will be used on a route wide assessment. For further information please call Simon Butler. Water, Ground & Environment compiled for internal use only

East West Rail UK Works have now reached a stage where earthworks and track laying are nearly complete on the eastern end of the route. The MOD Bicester sidings pre cast concrete retaining wall is now complete. Elsewhere overbridges, off-site highways and station construction works are well underway. Design work has now moved to the western end of the route where works are about to commence on track lowering through the Wolvercote Cutting & Tunnel. This will require underpinning of the tunnel abutments and use of modular block ‘Redi Rock’ retaining walls to support the cuttings. For further information please call Richard Down. Photo: View of the new MOD sidings at Bicester and twin track railway with supporting pre cast concrete retaining structure and regraded earthworks.

Stickle Tarn, Langdale Lake District We have submitted a proposal with GE’s Dams & Reservoirs practice to provide due diligence service to The Friends of the Lake District, who have expressed an interest in purchasing the iconic Stickle Tarn from the Lake District National Park.

Atkins Power has been invited to bid for the cable route study from Wylfa to Pentir, which includes 35km of route corridor and a crossing of the Menai Straits. GE’s scope of work would be to manage all survey activities, specifically desk studies, walkover surveys and onshore ground investigations. Although the original invitation included offshore surveys (geotechnical and geophysical) we have proposed that this be separated as the investigation in the Menai Straits is considered to be particularly challenging given the complex tidal conditions (double peak tides, 4m tidal range, constrained river channel and 5-8 knots currents) and the rocky sea bed. Contact Dean Tomlinson for more details Wylfa to Pentir cable corridor Wales

Water, Ground & Environment compiled for internal use only