The airport opts for underground construction
Rob Carr was hired to facilitate the installation of a new refueling line at Sydney Airport, using microtunnelling to do so.
Sydney Airport is modernizing its bays 83, 84 and 85 of the North Pond Apron, moving from stopover positions to active serviced bays, which will be able to accommodate arrivals and departures by bus.
To support active bay operations, the current infrastructure at these locations required upgrades in refueling capabilities, aircraft ground power, and preconditioned air.
To facilitate this refueling capability, an existing 450 NB fuel supply line was extended from its existing termination point to a new junction pit at Bay 83, and Rob Carr was selected to complete this complex installation work.
A trenchless solution
Rob Carr Construction manager Andrew Scarr sausername the project included the construction of a 523 m long reinforced concrete jacking pipeline DN900 using a pressure balance suspension microtunnelling to install it in three separate disks.
These trainings were carried out mainly on saturated soils consisting of silt, sand and backfill.
To complete the tunneling and allow the installation of the 450 NB fuel pipeline in the DN900 concrete pipe, Rob Carr also built concrete caissons in situ.
“The project also included the construction of two 9m ID caissons and two 4m ID caissons, which provided a dry and safe working environment for the dig a tunnel crews to conduct operations ”, hisusername Mr. Scarr.
“The boxes have also been chosen To minimize drying out ”.
Mr. Scarr sausername the construction of the second caisson with an internal diameter of 4 m was difficult due to its location, being adjacent to the runway, which required all the installations and equipment of the obstacle limitation service; however, at this location it was only 1.4 m above ground level.
To overcome this challenge, Rob Carr locally lowered the ground level, reduced the lifting / pouring heights on the caisson and only operated during the closure of the runway from 11 p.m. to 5 a.m. and the mobilization and demobilization of the installations and equipment required for each shift.
In addition, Mr. Scarr sausername some difficult drilling conditions were encountered with large amounts of foreign material encountered on the second line.
“This could be solved with the correct selection of microtunnel drilling machines (MTBM), a very experienced MTBM operator and the perseverance of the MTBM team to finally complete the line in line and level.
Mr. Scarr adds that Rob Carr was also responsible for the on-site management and treatment of assets, the management and disposal of borehole water and the establishment of concessions.
Working alongside Mr. Scarr was Rob Carr Director of Operations Justin Croucamp, with the two men responsible for overseeing the overall construction program and works management.
In addition, M. Scarr and M. Croucamp supported the Project Engineer and Project Supervisor, respectively Jamie Leal and Damian Coward.
“Although the conditions were quite difficult, the project was successfully completed and well ahead of the contract schedule. ”
For more information visit the Rob Carr’s website.
This article appeared in the March 2021 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.