This will provide a more resilient and longer lasting structure that supports the regions fuel and bitumen delivery demands.
CLIENT BRIEF/PROJECT CHALLENGES
The existing timber deck and substructure has been deteriorating with age. This project involved a new 6.75m wide access structure from land to a new 20m x 20m discharge platform for the oil and bitumen berth. The new structures achieve a 50-year design life. The site has limited weathered rock sitting over extremely hard granite bedrock below. To achieve the client’s budget socketing the piles into the bedrock needed to be avoided, whilst meeting the seismic design requirements of the New Zealand Building Code and Chapter 31F – Marine Oil Terminals (MOTEMS) of the California Building Code.
The new access structure and discharge platform has been designed to utilise an efficient construction methodology with open ended steel piles driven, followed by lifting the steel girders into place and lifting the precast deck panels onto the girders. This process allows the crane to drive forward onto the just constructed bent to drive the piles for the next bent and continue forward.
The design was undertaken with consideration of the varying weathered rock overlying the bedrock. A solution was developed to enable the crane to clean out those piles found to have insufficient embedment into weathered rock prior to the girders being lifted into place, with a second crew working along behind the crane to epoxy dowels into the rock at the base of the piles. This process minimises the time the crane is on site and the construction programme.
The efficient construction methodology reduces the risk of weather-related extensions of time and associated additional costs. The new access structure and discharge platform allows for a 100T crane to be used in the future to refurbish/replace the wharf areas adjacent to the new structures.
The use of epoxy dowels to provide embedment in the bedrock minimised the time and cost of conventional piling.
LIST OF PRIMARY SERVICES
- Structural Engineering
- Geotechnical Engineering
- Durability of marine structures
- Construction Monitoring