Case Study: Technology saves Sumatran expressway project 120 days, avoids $180m in losses

The adoption of advanced digital tools on the $3.5bn Trans-Sumatra Toll Road project played a “pivotal role” in meeting the expressway’s engineering challenges

The strategic implementation of cutting-edge technology has proven transformative for PT Hutama Karya, saving the construction giant 120 days and averting potential losses of $180 million on the ambitious Trans-Sumatra Toll Road project. 

This massive infrastructure endeavour, crucial for Sumatra’s economic development, faced formidable engineering challenges that were expertly navigated thanks to advanced digital tools and solutions.

The Trans-Sumatra Toll Road is an immense expressway that will stretch the length of Sumatra, from its northern tip to its southernmost point. It has more than 25 road sections in all, totalling 2800km.

It is considered crucial to the Indonesian island’s economic growth and regional integration and will cost around $3.5bn. After nearly a decade of work, the toll road is set to be completed by the end of 2024 (roughly half was operational by 2022).

Unsurprisingly, a highway that spans an entire country has some unique engineering challenges. Not least of these is navigating a constantly shifting and diverse terrain that throws up a wide range of demanding soil conditions. And that means a huge amount of data to process and integrate.

Leading Indonesian construction, toll road developer and operator firm PT Hutama Karya, was given the task of managing the strategic planning, design and construction management, with specific emphasis on the geotechnical data management that would underpin efficient, durable, and cost-effective construction.

However, their first attempts to tackle the scheme, using traditional data management methods, struggled to cope with the sheer scale of the project.

“We explored various approaches to address these issues,” said BIM Officer on the project, Deska Adi Pratama, “but managing large volumes of geotechnical data and integrating them into design decisions proved too challenging without advanced digital tools.”

After a number of trials, PT Hutama Karya settled on Bentley and Seequent applications to enhance project efficiency and effectiveness.

“That decision was driven by the need to streamline data management, enable 3D modelling and support collaborative design processes,” added Deska Adi Pratama. The Bentley ecosystem, including Leapfrog Works, MicroStation, OpenBridge and OpenRoads played a “pivotal role” in meeting the highway’s engineering challenges.

“Leapfrog allowed us to create accurate 3D ground models, optimising road alignments and earthworks based on detailed geological data. MicroStation, OpenBridge, and OpenRoads facilitated a model-based approach to road and bridge design, enabling rapid iteration and adaptation to changing project requirements.”

“Additionally, leveraging Bentley applications led to a 15% increase in productivity, translating to 6,000 work hours saved over the project duration… This enhanced productivity ultimately reduced project timelines by 120 days compared to conventional methods,” said Deska Adi Pratama.

Delivering ahead of deadline

The adoption of Leapfrog and collaborative design workflows reduced the project completion timeline by around 15%, estimated PT Hutama Karya. Being able to bring together the highway’s varied multidisciplinary teams for real time sharing of ideas and data, sped up decision making and kept everyone better informed.

The addition of PLAXIS to the solution set, in tandem with Leapfrog, was also key in providing robust geotechnical analysis of the subsurface. Across its vast and varied 2800km length, the highway exhibited an ever-changing set of soil conditions, complicating the process of achieving sure and consistent construction.

The combination of Leapfrog and PLAXIS greatly simplified the compilation of soil stratigraphy, and supported the implementation of a PVD soil improvement method.

This helped avoid potential losses of around $185m that could have arisen from technical failures in the construction.

Dealing with complex terrain

To tackle the challenge of mapping difficult terrains, the highway team adopted Beyond Visual Line of Sight (BVLOS) technology using drones to scan the topography. This improved both data collection and operational safety, especially in the most inhospitable areas.

MicroStation and iTwin Capture were pressed into service to process LiDAR pointcloud data and orthophotos respectively, providing precise Digital Terrain Models (DTMs) and detailed visual terrain representations – the foundations for accurate planning and design.

The easy integration of OpenRoads and OpenBridge Modeller became important in ensuring alignment and safety across such an extended piece of infrastructure.

The inclusion of slope adjustment tools within OpenRoads helped to optimise road alignment, while also cutting construction costs by improving material use efficiency.

“By utilising these digitally synchronised tools – and ensuring a ‘single source of truth’ – the entire geotechnical process became more structured and integrated… We could leverage Lean Construction principles to minimise reworks and reduce waiting times due to efficient data sharing.” said Deska Adi Pratama.

Turning geotechnical data into a major infrastructure success

The Trans-Sumatra Toll Road will have far-reaching benefits for the island and its population. Many of its 60 million people still live in small towns, effectively ‘off the grid’. As well as stimulating economic growth, the new roads will also encourage regional integration and support social development and community communication throughout the country. By reducing travel time and congestion, they will promote safer and more efficient mobility, extra trade and tourism, and improve access to essential services.

The adoption of Seequent and Bentley applications was instrumental in delivering the Trans-Sumatra Toll Road efficiently and cost effectively, concludes Deska Adi Pratama. “They empowered us to navigate complex engineering scenarios, optimise designs, and address the project’s unique challenges through advanced 3D modelling and collaborative design capabilities.”

PT Hutama Karya (Persero) were finalists in the Subsurface and Modelling category in Bentley’s prestigious 2024 YII Going Digital Awards in Infrastructure. Deska and the team are recognised for turning to Seequent and Bentley software solutions to manage data created by the Trans-Sumatra Toll Road: an immense expressway that will stretch the length of Sumatra, from its northern tip to its southernmost point.