A critical factor in any major construction or maintenance project is the accuracy of the pre-construction surveying. The client places significant trust in the delivery, and the implications poor results can have on the entire project are often understated.

Common delivery methods have been limited to fixed technology for many years, which has significantly limited accuracy. The impacts of which are felt in delays or re-measurements throughout a project.

Change is starting to be seen as the real value of improving technology is starting to surface, and there are a handful of major players requiring this new thinking from their delivery partners.

Being a leader of this change, McDonald Surveys have been working closely with clients to conduct pre-construction survey utilising a combination of technologies to execute Optical Survey Services in accordance with the clients and Australian Standard specifications and Engineering Procedures.

With regard to a rail example, we begin with the installation of control networks for topographic surveys and rail geometry capture for design, future rail installation, rail renewals, earthworks and tamping.

All control stations are traversed with a one-second, high precision Trimble S9 total station.  The Trimble technology suite is critical to delivering data at high levels of accuracy and ensuring the capacity for clients to model this data in various forms across a project.

Following this we undertake measurement of existing top of rail, including both left and right rails, with the Trimble GEDO Vorsys Dual Trolley Optical system for design. 

The topographic surveys we perform include pick up of top and bottom of ballast, existing formation, existing slopes and ground levels, drains and culverts, existing services, GDPs, all existing Insulated Rail Joints (IRJ’s), PI’s, ET’s, Stock Rail Joints (SRJ’s) and End of Set (ES) locations of turnouts, signalling equipment including asset protection instrumentation, as well as start and end of chainages of bridges. Lastly, set out and survey of pothole locations for reference to potholing dips from top of rail.

Critical survey is always performed of main road level crossings and diverge roads, all to Main Roads Standards, including start and end of road panels, road centre line, edge of pavement, shoulder, toe of existing embankments, plus existing drains and culverts.

To ensure the highest accuracy of outcome we also utilise UAV drones to capture detailed topographic surveys and capture video of existing rail and embankments using GoPro technology.

This combination of technologies is executed within the same timeframes as traditional pre-construction survey and it provides clients with an excellent data set for them to begin the construction phase of any project.

If you have a project that could benefit from the advantages of advanced technology when it comes to pre-construction survey, please contact us today for an initial discussion .