AT GROUND LEVEL
In this article composed by Kevin Garcia , Trimble General Manager , Civil Specialty Solutions ; Riley Smith , Trimble Marketing Director , Monitoring and Tunnelling ; and Doug Reichard , Trimble Director , Industry Strategy – State / Federal Government , we explore 3D technology ’ s role in aiding and monitoring ageing bridges .
Ageing bridges highlight the need for innovative 3D technology that delivers construction-ready data
T he 2021 American Society of Civil Engineers ( ASCE ) Infrastructure Report Card gave US bridges an overall grade of ‘ C ’ as the lifespans of these critical structures come to an end and prior performance standards prove inadequate due to increased traffic volumes and heavier weight loads . To address this growing threat , the industry is adopting improved methods of inspecting , monitoring and constructing bridges , including scanning and mapping technology that provides valuable insight into the challenges associated with ageing infrastructure and the safety of transportation networks .
The dismal condition of thousands of bridges is driving the demand for accurate asset data to gauge current conditions , prioritise public safety and compare options for rehabilitation versus new construction . With the adoption of 3D bridge building information modelling ( BIM ), state departments of transportation ( DOTs ), government agencies and contractors are addressing this crisis with improved end-toend asset lifecycle management .
The Kentucky Transportation Cabinet ( KYTC ) provides an illustrative example of how digital technology is playing a critical role in addressing failing bridges . In 2018 , the Kentucky state legislature passed an ambitious highway plan , allocating US $ 350 million to renovate or replace 340 bridges over a two-year period .
“ That was about five times more than we typically addressed in a single year ,” said KYTC Programme Manager Royce Meredith .
With the accelerated timeline , KYTC turned to consulting partner Stantec , which helped the project team implement cloud-based construction management software to handle the bridge projects . The robust capital programme and construction management software allowed the team to streamline each phase of the process – from screening to developing plan specifications and estimates , bidding , and project management .
“ We developed a full , connected project workflow for KYTC from screening through project closeout in Trimble e-Builder – all in less than a year ,” said Dr Tony Hunley , Stantec ’ s Bridge Practice Leader . “ To date , that workflow has been utilised on more than 400 bridges .”
Unique challenges posed by bridges
Bridges are a critical part of our transportation network ; however , their complex and often hard-to-reach structures make frequent inspections difficult and costly . Even temporary closures cause disruption to normal traffic flow and supply chain routes , and if issues are identified , closing bridges for repair or replacement can cause even bigger problems . By streamlining workflows during the design , planning and construction phases , project managers seek to reduce inconvenience and cost , and respect the project delivery schedule . Additional benefits include compliance with rules and regulations , reducing rework , and increasing safety for both workers and bridge users .
Capturing the digital data of existing bridges using laser scanners , total stations , drones and Global Navigation Satellite Systems ( GNSS ) helps expedite surveying and provides data sets that are easily shareable between several departments . By creating a bridge BIM , all relevant data acquired can be integrated with information from various sources to evaluate the bridge ’ s condition and maintenance needs . This detailed model helps support informed decision-making and prioritises future work activities .
In the US , federally funded projects must meet certain sustainability requirements that emphasise best practices to reduce
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