Hale Street Link Associated Project - Brisbane City Council

Hale Street Link Associated Project

Project Summary
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.

The Challenge

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.

The Solution

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.
A 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 FSL.
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 Result

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).