Dar es salaam Port - Foundation Pile repair
Tanzania Port Authority (TPA) commissioned berth expansion works at the Daresalaam port, this involved construction of new berths to allow docking of more Ships. As part of this project, Somers Engineering was appointed to carry out repair and rehabilitation works on the older berths that exhibited deterioration.
The repair works
The works entailed underwater foundation piles repair on member that had shown numerous defects on the older berths. Working on the foundation piles required the working hours be based on changes in tide levels through the day as per the tidal chart. A total number of 36 piles of varying sizes and scope of works were considered for retrofitting.
Retrofitting works was carried out over an 8-month period, and it involved the following.
Micro pilling works
Installation of four-355.6mm diameter micro piles around piles that were showing severe defects and deterioration. The micro piles were driven into the sea bed as per design, to support the design load of the original pile.
Hydro-demolition utilises high pressure water to remove the defective concrete while at the same time allowing the steel reinforcement beneath to remain intact. This vibration-free technique prevents cracking and micro fracturing of the structure during the process.
This is the removal of sediments and debris from the bottom of the sea bed. It is a routine done to clear the area where the micro piles are driven into the sea bed.
Is a technique used to control the corrosion of a metal surface by making it the cathodic side of an electrochemical cell. This is done by connecting the metal to be protected with another more easily corroded metal to act as the anode of the electrochemical cell. Anodes were connected to the exposed steel reinforcement for corrosion protection.
Jacketing of piles.
Jacketing is a widely used method of increasing the capacity of columns and beams by placing a concrete jacket around the original member.
This was done to piles showing extensive deterioration.