WHY COLLECTING SUBSURFACE UTILITY INFORMATION IS CRITICAL FOR INFRASTRUCTURE PROJECTS

To prevent issues down the track, city managers and asset owners can take a proactive approach to their infrastructure projects by building a comprehensive utility map of the entire city – that can be used across a range of infrastructure projects to reduce utility strikes and improve cost and delivery timeframes.

The Problem

Most local councils and construction teams have very poor visibility into the state of their subsurface infrastructure. Network and utility owners are reluctant to share accurate, upto-date data on their subsurface assets, and unlike the aboveground environment, information on the subsurface is difficult to procure and analyse without specialist utility surveying. Inaccurate information about the subsurface is linked to project cost overruns and timeframe blowouts internationally. In New Zealand, a recent cycleway project lost 194 working days due to the discovery of buried subsurface utilities, including power, gas and telecommunications lines that were previously undocumented. Closer to home, a post-mortem report on the Sydney Light Rail scheme found the project could have been built 1.5 years quicker if the team had reliable underground utility information.

CASE STUDY: A NEW APPROACH

A major transport and urban rejuvenation project in Wellington, New Zealand, is taking a new approach to the problem.

Reveal was commissioned to proactively map the underground of the CBD and combine the resulting rich information into a utility asset model that could be shared with all the project stakeholders across a range of planning, design and construction functions.

This proactive mapping effort has already delivered positive results, as Reveal was able to find several voids below the road surface of Jervois Quay that posed a danger to road traffic as well as critical infrastructure.

Engineers were able to quickly respond and repair the damage, while minimising the impact on the community and businesses.

Benefits

In a global survey of infrastructure projects by Geo. the availability of subsurface information produced unprecedented cost and time savings including bid reductions of 10 per cent, schedule reductions of 30 per cent, and labour reductions of 50 per cent, along with zero delays, damages, or change orders.

Geo.works stated that, “Based on a proof-of-concept trial in London conducted by Les Guest Associates, it was estimated that construction costs could be reduced by 10-25 per cent if the location of all underground infrastructure and subsurface conditions were known in advance of construction.”

With the price tag on major infrastructure projects running to the hundreds of millions of dollars, it’s clear that accurate subsurface information can be a massive cost saver, and reduce project times.

Be Proactive Early

Cities have been tasked with major infrastructure upgrades to adapt to climate change, reduce carbon emissions and deal with urban intensification over the coming decades.

Proactive subsurface risk management can yield massive savings if undertaken early in the process, and can help deliver savings to ratepayers, reduce the impact on citizens, and deliver prosperous, sustainable development outcomes.