Constructex have fully refurbished a timber jetty which was in a state of disrepair.
The jetty comprised timber pile bents, a Bailey Bridge, Bailey linkspan and Steel Pontoon.
The timber piles were suffering from loss of section from a combination of marine borer and physical erosion due to the strong currents.
The extent of section loss was unknown in areas less obvious than the above. Marine borer are know to penetrate deep within voids and shakes leading to significant section loss with severe consequences for structural capacity. It was therefore necessary to determine where and to what extent section loss had occurred prior developing the remedial scheme. The Digital microProbe developed by Sibtec Scientific was used to obtain a detailed dendrochronology. This permitted Constructex to accurately account for the section properties and target the maintenance spend efficiently; ultimately making the project economically viable.
The solution was to design a method of utilising the existing embedded pile without relying on the above ground pile length. This proved to be a cost-effective method of repair for a jetty which needs a relatively minor extension to its operational life.
Bracing throughout the structure was also replaced after the pile was sufficiently strengthened.
The Bailey Bridge components had suffered a reduction in moment capacity due to loss of steel thickness on critical structural elements. Additional steel was welded to the section to enhance the capacity of these critical elements.
The structure has now been given another 10 years of life subject to ongoing maintenance requirements.