The IKN Toll Road to Indonesia’s ambitious new capital, Nusantara, brought a very special set of challenges: a remote location, steep terrain, a flood-prone river to bridge, and strict environmental requirements.
Yet by using a combination of Seequent and Bentley software, contractors PT Hutama Karya not only managed to accelerate construction time, but also reduce carbon emissions, and save an estimated $90 million by avoiding costly reworks on a landmark national project.
70%
Shaved off data processing and decision–making times, helping to hit deadlines and save costs.
$90 mil.
Overspend avoided thanks to analysis that prevented potential flooding, embankment collapse, damage to electricity towers and costly road reworks.
83%
Reduction in the project’s carbon emissions through smarter transport and soil usage.
The long road to Nusantara
The core governmental centre of Nusantara is a major strategic project for Indonesia, which aims to harness innovation and technology to make it the world’s most sustainable city. But it is also meant to be an inspiration – the planet’s first modern forest city, sympathetically sited and environmentally constructed in the dense woodlands of Balikpapan in the East Kalimantan province.
It’s an important step for Indonesia, not just because of the economic boost it will bring – a projected 47% rise for East Kalimantan specifically, with a potential 11% lift for the nation as a whole – but also because it is closely wrapped up with Indonesia’s national identity to have a powerful green economy that reflects its landscape and culture. Practically, the road will form a key link between government, energy, oil, and gas sectors within the growing East Kalimantan logistics hub.
How Seequent and Bentley products saved time, money, and CO2
PT Hutama Karya is the lead contractor for the 13.4 km section 3A, including a 920-metre bridge, in a project area covering 110 hectares of steep terrain and dense forest. A tight construction schedule and the strict environmental requirements of building in such an area called for the most comprehensive modelling and geotechnical analysis technology.
Hutama selected Bentley’s ContextCapture to process aerial data and forge it into an accurate reality mesh of the entire site – a process that liberated seven days of the project’s data processing time against conventional methods. Meanwhile, integrating Leapfrog and PLAXIS to perform 3D geotechnical modelling and analysis helped save more than $90 million in rework costs. This included:
- By using PLAXIS and GeoStudio to analyse the 1:2 slope inclination, the decision to opt for a soil nailing treatment avoided losses of $2.4million that could have been caused by damage to electricity transmission towers, and resultant outages
- In the mobile crane foundation area, the use of PLAXIS to understand river water rise and the risks of slippage saved $154,000 from girder overturning and embankment repair, as well as avoiding losses of $1.6 million from delays to the bridge construction
- Analysing the clay soil embankment with PLAXIS helped prevent construction failures that would have resulted in a $43 million rework for the 6.4km of the main road.
- This analysis also showed that using the existing soil as embankment would reduce the distance travelled by dump trucks from 30km to 5km, cutting the project’s carbon emissions by 0.43 tons of CO2 per day.
All told, PT Hutama Karya estimated that the use of Bentley and Seequent solutions, working in tandem, cut data collection and processing times by 70% compared to conventional methods. Decision time on resolving the key slope issue was also trimmed by 70%.
Tricky soil, tough terrain, and a risk of flooding
With a large land area characterised by contoured terrain and dense forest cover, it was decided to conduct an aerial survey using LiDAR to generate accurate data with minimum density of one ground point per square metre. The LiDAR point cloud was then processed using ContextCapture. Borehole data around the main transmission tower supplying electricity to East Kalimantan was processed by Leapfrog to visualise existing contour conditions and soil layers in the area.
From the visualisation in Leapfrog, GeoStudio was used to determine the appropriate treatment for the slope. The initial suggestion of vegetation treatment was excluded as having an insufficient safety factor, with soil nailing employed instead – a critical solution in a landslide area that could affect the power supply for the region.
The river’s high-water level presented a risk that overflow into the bridge’s work area would damage materials and equipment in the stockyard. Working with PLAXIS analysis, the Hutama team opted for a 12-metre-deep steel sheet pile to be installed at an intersection point between embankment and river, and studies showed this achieved the required safety factor.
The key part of a critical digital transition
In conclusion Hutama Karya said that the Bentley and Seequent tools: “not only produce accurate geotechnical analysis but also assist timely project completion, which is a crucial part of Hutama Karya’s digital transformation process in developing sustainable infrastructure. This contributes to ecological sustainability, increased investment value in the new capital city infrastructure, economic growth in Indonesia and plays a role in mitigating global climate change.”
Facts and stats for the IKN Toll Road
- Segment 3A of the IKN toll road, from Karang Joang to KKT Kariangau, will stretch for 13.4km
- Construction time is 660 days
- Contract value is $223 million
- It includes an at-grade section of 9,940 metres and an elevated slab pile of 3,200 metres
- There is a 930-metre girder bridge across a 90.5-metre width river, featuring a high-water level
- There are six overpass locations and one junction
The hopes and history of Nusantara
Nusantara is the future capital of Indonesia and is scheduled to be inaugurated later this year (hopefully to coincide with Indonesian Independence Day). It will replace Jakarta as the centre of government, which has been plagued by flooding. (Though Jakarta’s still growing population won’t be moving, and it’s feasible the city could yet become the world’s largest.) Situated on the east coast of Borneo, Nusantara will sit on a bay, in a hilly, forested landscape, taking up around 2,500 sq km.
The idea of moving Indonesia’s capital has been in play since the 1950s, but it was President Jokowi who finally ratified the project in 2019. Construction was fully underway by mid-2022, with estimates of the total workforce varying from 100,000 to 200,000.
PT Hutama Karya is Indonesia’s largest state-owned enterprise in the infrastructure sector, and was a Founders’ Honors Recipient in Bentley’s prestigious 2023 Yll Going Digital Awards in Infrastructure, in the Subsurface Modeling & Analysis category. Founders’ Honors are presented to a small number of exemplary projects, individuals, and organisations the inspire Bentley’s mission of advancing the world’s infrastructure while sustaining both the global economy and the environment.