Our Civil Engineering Director was invited to table suitable earth retention options for a number of Guildford to London Waterloo main line stations where platform extensions had already been constructed leaving exposed excavated banks unsupported in London Clay tight to the rear of the existing platforms themselves. Through a series of meetings and discussions with the Contracts Engineer and Construction Director of Principle Contractor C Spencer and Railtrack Senior Civil Engineers at their offices in Waterloo and on each of the four sites at Guildford, Claygate, Oxshott and London Road, a modular block faced gravity retaining wall rationalised solution was proposed and eventually adopted throughout the scheme.
Access to the working areas was severely limited and was only achieved by using lightweight equipment, hand tools, batching the backfill and footing concrete on site and by carefully sequencing the work due to build activities being in close proximity to a live mainline railway and the general commuting public. Management of Health and Safety was of paramount importance, with daily briefings at the start of the shift and debriefings at the end of each day's work key to the efficiency and safety of the workforce and general public.
After initially carrying out a retaining wall specific interpretative ground investigation report to determine appropriate soil parameters and groundwater conditions for design purposes, we produced internal stability analyses and typical section drawings for client AIP approval prior to the commencement of the works on site. Over 150 linear metres of this type of retaining walling of up to 3m in height was built on this contract with benefits to permanent slope stability, aesthetics and client satisfaction achieved.