10.30 Red Theatre The AB Chance Helical Pulldown Micropile system in use for underpinning and new construction Andrew St Johnston, managing director, Sub-Surface Technologies The presentation will describe the use of AB Chance's Helical Pulldown Micropile system to underpin a nineteenth century gatehouse to Alnwick Castle, Northumberland. It will show the limited access capabilities of the system along with the lack of soil disturbance caused by the helical screws during ground penetration. The presentation will also cover the use of the micropiles in construction of a major extension to a commercial building near the east coast of England.
11.30 Red Theatre Foundations for the Olympics - Roger Bullivant carries the Torch!
John Patch, director, Roger Bullivant The investment in new construction for the London 2012 Olympics is huge, both in terms of buildings and infrastructure. The vast majority of the build will occur on brownfield or poor quality sites. The need for the construction of innovative, costeffective, rapid, premier-quality, permanent and temporary foundations is immense. This seminar will seek to identify the challenges in the ground and the solutions available from foundation contractor Roger Bullivant. The company specialises in dealing with difficult access, restricted headroom, piling in highly sensitive areas and dealing with complex ground conditions.
12.45 Blue Theatre Construction of a secant piled retaining wall using restricted access equipment Richard Holmes, group managing director, Van Elle Foundation contractor Van Elle was contracted to form a secant piled retaining wall in extremely restricted conditions to deepen a basement to accommodate a new art gallery in central London. Work was particularly challenging because piles had to be installed in headroom of 3.5m; Van Elle overcame this by using three restricted access piling rigs, a modified lorry for deliveries and a mini crane. The presentation will cover design, construction and testing of the works, focusing on the equipment and techniques used.
13.45 Blue Theatre A new approach to subsidence control: Ground improvement rather then piling or underpinning Bill Stevens, technical sales manager, Uretek UK Over the last 25 years, Uretek has invented, developed and refined polymer ground engineering technology and now uses resins for a broad range of applications worldwide. Two main processes are available: slab lifting technology; and the deep injection process, which offers ground improvement to greater depths as an alternative to piling or underpinning. Key advantages of both processes are speed of operation and minimal disruption, dust or mess. The presentation will cover principles of polymer ground engineering technology; comparisons with alternative ground engineering strategies; an explanation of the Uretek method and its application; suitable soils and cases for treatment; and project histories.
14.30 Red Theatre A case history of the use of Eurocodes for the design of underground structures David Beadman, principal engineer, Tony Gee & Partners In a few years time UK engineers will have to design to Eurocodes.
This case study examines the use of the codes on a metro project between 1996 and 1999, when the codes were in their infancy. The presentation discusses the experience, the difficulties encountered and the benefits gained by the project, with reference to the geotechnical design of the deep underground stations, where Eurocodes 1, 2 and 7 were used for the design of the retaining walls. The observational method was also adopted for the construction of one station, based on the requirements of Eurocode 7.
14.45 Blue Theatre Remediation of brownfield land Nick Gorst, Concrete Centre regional engineer Midlands & South Wales The latest estimates indicate there is up to 300,000ha of brownfield land in the UK. Stabilisation and solidification using cement-based materials offers an alternative solution to dumping in landfill that stabilises and solidifies contaminants, while simultaneously improving ground engineering properties. The seminar will introduce technology and cover major issues relating to site characterisation, risk assessment, process methods, performance testing and monitoring. Numerous case studies from the UK and overseas will be presented to demonstrate this remediation strategy in practice.