This category is for schemes with a geotechnical value of less the £500k that demonstrate innovative design, value engineering, involvement with stakeholders and community, and efficient delivery.
Entrants were also expected to show their credentials in sustainability and health and safety.
Aecom – Carsington wind turbines, Derbyshire
The Carsington project involved the development of a wind farm over a broad tract of limestone grassland on a moderately undulating upland plateau in Derbyshire, within the Peak District National Park. Due to unforeseen difficult ground conditions additional ground investigations were required and bespoke ground improvement was necessary at each turbine location. Aecom successfully designed and managed an array of ground investigation techniques, including trenching, rotary coring and open-hole drilling, directional proof drilling of voids, cable percussive boring, down-hole CCTV survey and geotechnical in-situ and laboratory soil testing. Using a combination of geophysics techniques together with a survey of the mine-workings and reassessment of ground records allowed a targeted intrusive investigation to be planned, which involved open-drilling and coring, trenching, and down-hole CCTV surveys.
Aecom – Unstone Bank railway cutting, Chesterfield, Derbyshire
Following a significant landslip in the hillside above the Midland Mainline Railway, Aecom was appointed to undertake a desk study and geomorphological assessment, emergency design of remedial works and detailed engineering design of permanent remedial works. Aecom, in collaboration with Construction Marine and Network Rail, designed and supervised the construction of the emergency remedial engineering works. This comprised the construction of a granular shear-key, 5m wide by 5m deep, perpendicular to the track. The permanent landslip stabilisation works comprised the installation of a further three granular shear-keys in the hillside above the railway, with a series of deep counterfort drains to collect and dissipate groundwater that had been a problem at the site.
Donaldson Associates – Stabilisation of a soil pillar adjacent to Eastern Ticket Hall at Bond Street Crossrail Station
For this project Donaldson Associates undertook geotechnical works relating to the stabilisation of a soil pillar adjacent to the Eastern Ticket Hall at Bond Street Crossrail station. The geotechnical solution was designed to address the risk of soil failure and the constraints for installation. A reinforced earth mattress was created to intercept the vulnerable soil column and enhance the capacity of the soil by spreading the loads. This was achieved using an array of overlapping grouted pipes installed near-horizontally from the masterplan shaft. According to the company, this approach had numerous advantages: the complex geometry accommodated the solution’s installation; the solution could be installed offline; there was no delay in achieving ring closure; there was no impact on adjacent permanent works; and contingency “toolbox items”, including spiles and pocket excavation, were available if problematic ground conditions were encountered locally.
Pell Frischmann – Hill Road Studios, London
This project involved the design and construction of a detached dwelling in St Johns Wood, London. The majority of the living area consists of an extensive single storey basement which occupies the entire footprint of the site. The basement was constructed from in-situ reinforced concrete and was designed to support a reinstated garden area including mature height trees. A construction methodology was developed to allow the basement construction to be undertaken entirely by hand excavation with no proprietary structural support or the use of any equipment that was not able to be handled manually. Pell Frischmann was responsible for all the structural design, permanent and temporary works, and construction methodology. Pre-construction work included ground movement assessment, advice on party wall matters, and monitoring.
United Utilities – Risks associated with reuse of a tunnel drive shaft at Anchorsholme Park, Blackpool
The works at Anchorsholme Park, near Blackpool, were part of United Utilities’ Fylde Strategy to address environmental issues driven by the EU Bathing and Shellfish Water Directives to improve water quality. Phase 1 works required improvement of the hydraulic connection to the Fylde Coast Tunnel (FCT) to achieve a spill frequency position. To facilitate this connection, investigations were undertaken to determine the viability risk and opportunity to recover and modify a temporary shaft (12A) at the site. Based on review of the developed ground model from United Utilities’ advanced investigation works, it was concluded that the risk associated with works in this shaft were too great and too difficult to manage during construction and did not deliver the required benefits within AMP5.