Hale Street Link Associated Project
Road reconstruction and improvements
associated with the Hale Street Link Project from Peel Street to Vulture Street,
along Merivale and Cordelia Street in South Brisbane. Service co-ordination and
impact assessment was required for all underground services.
Existing underground services had to be identified, and service covers compared
with existing crowns to NSL (including designed FSL). After survey, CTTV of BCC
stormwater and Dial Before You Dig information was gathered, as well as service
locators for pot holed services at regular 20-40m intervals in the work area of
2-3km of road, over 1km2 in busy South Brisbane.
Identification of critical services (age, depths, and condition) was required
for BCC and service authorities to determine relocation costs in advance of road
works. As a result, it was necessary to compare any relocation costs estimated
by authorities’ versus redesigning, to avoid excessive costs.
After trialling initial manual methods, considering time restraints, the size of
area, number of services within the area and manual work required, while
reducing manual human errors, a better automated method was required.
Designers used 12d Model software to 3D model all actual services in location,
depths sizes, and number of conduits to allow for assessment of critical covers
and impacts with existing services and proposed works.
A 12d macro solution was developed to identify, label and report existing
critical crown depths (AHD) for services to NSL (>0.6-0.75m cover adopted) which
also included a comparison to the proposed design FSL. An input of left and
right corridor search distance width allowed one control line chainage
reference. This meant that each depthed vertices/fitting could be identified in
coordinates, chainage, and the change in height from NSL and design FSL, whether
positive or negative.
The Work Area was
divided in to four areas of manageable sizes. A unique naming, labelling and
identifying system was required for each service string/model and node/vertex by
a numbering and prefix ID, using an automated labelling attributes macro, prior
to running the main service depth macro.
report was computated with each potholed vertex for depths of services, MH, pit
corners, water values, metrer, fire hydrants, gas valves, etc., so that each
node could be identified in coordinates with the change in height to the design
Reports for all service information
were collated with data sorts in Excel tables to display on individual service
plans, showing 50mm depth range polygon differences for a visual image of NSL to
FSL changes. This allowed quick identification of problem areas with each
service, assisting project managers and service authorities to identify
relocations required, with confirmation of existing and design cover.
Being armed with detailed information on existing service covers, including the
proposed design FSL, allowed easier communication with authorities, including
boldly requesting funding for relocation of existing shallow services, saving
both BCC and ratepayers money, and authorities investigation and assessment
decision time, hence further reducing costs and expected delays with any service
works and programming.
One drawback was
sorting too much information if gathered at once, initially with too many
symbols, if all checking macro elements were used at once for multiple services.
Hence adopting a model naming convention and running with one service at a time
was found to be best.
The final product was a comprehensive assessment of all services, critical
depths allowing determination of the effects of existing and proposed design
cover with limited manual calculations. These plans allowed assessment and
decisions to be made for service authorities, and client and project managers to
make decisions on design and redesign due to service relocation costs. Plans
were also used in estimating and allowing BCC and service authorities to make
quicker impact decisions for their own as-constructed assets prior to works
(special thanks for program works by Peter Murray of BCC).
Download this Case Study as a PDF