28 BAUER machines on a 142 km high-speed railway: what the Yerköy–Kayseri foundations show
Türkiye is building a new double-track high-speed line between Yerköy and Kayseri in Central Anatolia. The specialist foundation works are being carried out with a fleet of 28 BAUER machines. For contractors and engineers planning major linear infrastructure, the interesting part is not the machine count — it is how method, depth and fleet composition were matched to the ground and to the structures the line requires.
The project
The Yerköy–Kayseri line is 142 km long and designed for speeds of up to 250 km/h. Groundbreaking took place in July 2022. Along the route, 15 tunnels, 118 underpasses, 18 bridges and two stations are being constructed.
BAUER states that after completion and commissioning the line is expected to carry up to 11 million passengers a year and approximately 650,000 tonnes of freight. Travel time between the two cities is expected to fall from three and a half hours to under one hour, with Ankara–Kayseri journeys reduced from about seven hours to around two.
The specialist foundation engineering works for the entire line were awarded to a joint venture of Doğuş, Çelikler and Özkar. BAUER's sales manager Wolfgang Ziegltrum notes that Doğuş has been a BAUER customer for more than 20 years.
The fleet and the methods
The 28-machine fleet comprises:
- BG 33, BG 36 and BG 45 rotary drilling rigs
- RG 22 S and RG 27 S pile drivers
- CMS 30 mixing plants from BAUER MAT Slurry Handling Systems
Two distinct ground techniques are running in parallel.
The drilling rigs are installing piles down to 30 m using the Kelly drilling method. These piles serve two purposes: ground improvement along the rail alignment, and foundation elements for bridges and viaducts.
Alongside this, single column mixing (SCM) is used to improve the soil. A mixing tool blends the in-situ ground with a binding agent injected during penetration. On this project the SCM columns are being installed up to 31.5 m deep — a notable depth for the method.
The presence of CMS 30 mixing plants in the fleet is the detail that ties the two techniques together: the binder supply for the mixing columns has to be produced and delivered continuously on site, at a rate that keeps pace with the rigs.
What this actually demonstrates
Three things are worth drawing out, none of which is about a single machine.
Method selection is driven by the structure, not the machine catalogue. Bored piles installed by Kelly drilling and soil improved by column mixing solve different problems. Bridge and viaduct foundations need discrete load-bearing elements. Long embankment sections need improved bearing capacity across a corridor. The fleet contains both rig types because the line requires both answers.
Fleet composition is a production decision. Twenty-eight machines across three rig families and a mixing plant type is not a shopping list; it is a sequencing decision. Drilling rates, binder production, column depth and the movement of rigs along a 142 km corridor have to be planned as one system.
Depth changes the plan. SCM columns at 31.5 m and Kelly piles at 30 m are at the deeper end of what these methods are typically asked to do. Depth affects verticality control, spoil and binder handling, cycle time and quality assurance.
Relevance to projects in Uzbekistan
Uzbekistan is investing in rail, road and industrial infrastructure, and the underlying engineering questions on a long linear project are comparable: what the ground requires, which foundation method suits each structure, and whether the fleet can sustain the required production rate along the alignment.
That comparability should not be overstated. Ground conditions, seismic design requirements, binder availability, haul distances and project specifications differ by site and by country. The Yerköy–Kayseri project does not demonstrate that the same fleet or the same methods would be correct on any specific project in Uzbekistan. It demonstrates how those decisions were structured on one major line.
For projects in Uzbekistan, the evaluation may also need to consider mobilisation distances between Tashkent and regional sites, summer temperatures affecting binder and concrete work, dust and access conditions on unfinished corridors, and service planning for a rig fleet operating far from a maintenance base.
What a project team should establish first
Before any rig class is discussed, the following usually determine the answer:
- geotechnical investigation results along the full alignment
- the structures to be founded, and their load requirements
- required pile depth, diameter and verticality tolerance
- whether ground improvement is specified, and by which method
- binder or concrete supply capacity and continuity
- production rate required to meet the programme
- access, working platform and corridor constraints
Talk to RENTEK
RENTEK supplies BAUER foundation equipment in Uzbekistan. Contact RENTEK to discuss equipment supply options, configuration requirements and project documentation. Where a technical service requirement arises, RENTEK receives and coordinates the request, while technical diagnosis and agreed service work are performed through KTS INDUSTRY where applicable.
Official source: BAUER Maschinen GmbH project reference, "Yerköy-Kayseri high-speed rail line."