Frankham specified site investigation works at Ridham Dock to determine the long term properties of the soil and analysed the overall stability of the wall, which was determined as marginal.
Robert Brett then extended Frankham’s appointment to include the design of remedial works to increase the stability of the dock wall.
Surveys had determined that the wall was basically in sound condition and we specified steel sheet piling to retain the toe of the wall. The piles were driven into the underlying clay, with the heads of the piles tied into the existing construction at just above low water level. Ground pressures on the wall were reduced, and additional stability was provided by increasing the strength of the retained soils, using a soil mixing technique.
Previous stabilisation works had introduced a mass concrete toe in front of the wall and a reinforced concrete suspended jetty was supported off the mass concrete toe, to provide protection to vessels using the berths. As a result of ageing, the jetty structure had deteriorated and the support columns and beams were suffering from corrosion of the steel reinforcement and spalling of the concrete. Frankham’s involvement included the specification of the necessary repairs and strengthening of the jetty part of the structure, including the knuckles at the outer end of the dock.