Design of underground structures for rail, road, energy and water supply, from early studies through construction, and independent checking of structural designs.
Planning of a new drinking water transmission main for the City of Zurich. Comparison of seven construction variants (1A–2B) using microtunnelling, horizontal directional drilling, TBM and open-cut construction.
Switzerland · since 2024 Project Manager / Senior Tunnel Engineer Client: City of Zurich
Pumped storage plant in northern Israel with a single 156 MW pump turbine: upper and lower reservoirs, powerhouse cavern, low- and high-pressure waterways, surge tank and access tunnel.
Led a team of three engineers (scope, budget). Design of the steel liner in the high-pressure shaft, high-pressure tunnel, low-pressure tunnel, access tunnel and surge tank; contribution to the powerhouse cavern
Project phases
Detailed design
Effluent Outfall Tunnel, Los Angeles
Effluent outfall tunnel for the Joint Water Pollution Control Plant (JWPCP), about 12.9 km (8 miles) long, about 5.5 m (18 ft) in diameter. First use in the USA of post-tensioned segmental lining, over up to 40 % of the alignment.
USA · 2021 – 2022 Senior Tunnel Engineer Client: Dragados USA
Details
Cost / period
USD 630.5 million, 2019–2025
Services
Design of starter and tail tunnels for the TBM launch; risk assessment and mitigation design for the TBM drive in squeezing ground
Project phases
Detailed design
All reference projects (20)Show fewer projects
Gare de Lausanne (Nouveau Métro)
As part of the SBB programme «Léman 2030», Lausanne station is being comprehensively renewed: new platforms and underpasses while train operations continue. First section in service in 2030, full completion by 2037.
Switzerland · since 2025 Project Manager Client: SBB / CFF
Details
Services
Independent checking of the structural calculations (equivalent to a Category 3 check, UK): bored pile walls, micropiles, top-down construction, excavation support; geotechnical inspection; risk management
Project phases
Preliminary design / Tender
Alto Maipo Hydropower Project
Short-term assignment of three months during construction.
Chile · 2025 Senior Tunnel Engineer Client: Strabag AG
Details
Services
Evaluation and assessment of a tunnel collapse
Project phases
Construction
Cargo sous terrain
Underground network for automated, electric freight transport in Switzerland. The design covers a 75 km single-tube tunnel, mostly bored by TBM with SCL sections, plus shafts and portals.
Risk analysis, construction concepts, bid preparation, variant planning
Project phases
Preliminary design / Tender / Bid
French Hill Tunnels, Jerusalem
Two twin tunnels with a total length of 3.5 km beneath one of Jerusalem's busiest junctions, passing under roads 1 and 60, the Uzi Narkis bridge and the LRT tracks. Excavation with low rock cover and in fill, temporary access tunnel, up to 12 headings at the same time.
Design of the false ceiling connections and reinforced concrete design
Project phases
Detailed design
Purple (D) Line, Section III, Los Angeles
Heavy rail line of about 3.7 km (2.32 miles), double track, with tunnels and 13 cross passages. The cross passages require dewatering and ground improvement; excavation and support follow SEM principles.
USA · 2018 – 2021 Senior Tunnel Engineer Client: Los Angeles County Metropolitan Transportation Authority (LACMTA)
Details
Cost / period
USD 1.3 billion, 2020–2026
Services
Analysis and design of the cross passages
Project phases
Detailed design
Vienna metro U5/U2, stations
Two new underground stations in the city centre, beneath multi-storey commercial buildings.
Austria · 2017 – 2018 Structural and Geotechnical Engineer Client: Wiener Linien GmbH
Details
Services
3D structural analysis of the stations; settlement analysis of the surface buildings
Project phases
Tender design
Koralm Railway, Granitztal tunnel chain, BL 50.4
Total length about 6.5 km. The cut-and-cover tunnel, about 600 m long, connects two mined tunnels of the high-speed line.
Austria · 2015 – 2017 Structural and Geotechnical Engineer Client: ÖBB
Details
Services
Analysis and design of the cut-and-cover tunnel and the tunnel bridge
Project phases
Detailed design
Geisswand road tunnel
Road tunnel of about 2.2 km, two lanes, excavated cross-section 76 m² (NATM).
Austria · 2015 – 2017 Structural Engineer Client: ASFINAG
Details
Services
Rehabilitation of floor heave caused by swelling; design of the road pavement against swelling pressure
Project phases
Detailed design
Arlberg road tunnel
At 13.976 km, Austria's longest road tunnel (S16, Tyrol–Vorarlberg).
Austria · 2015 – 2016 Structural Engineer Client: ASFINAG
Details
Services
Structural analysis for the tunnel rehabilitation (components of the rehabilitation concept)
Project phases
Detailed design
Gleinalm road tunnel
Motorway tunnel on the A9 Pyhrn in Styria, 8.32 km long. New second tube (opened 2017), followed by rehabilitation of the existing tube.
Austria · 2014 – 2015 Structural Engineer Client: ASFINAG
Details
Services
Analysis of the final lining of the new tube; rehabilitation of the existing tube
Project phases
Detailed design
Semmering Base Tunnel
Railway tunnel of 27.3 km between Gloggnitz and Mürzzuschlag, two tubes, in difficult geological conditions.
Austria · 2012 – 2016 Tunnel Engineer Client: ÖBB
Details
Services
3D analysis of the drive through the fault zone; analysis of the NATM and TBM cross-sections; analysis of the final lining
Double-deck road tunnel of 5.4 km beneath the Bosphorus, down to −106 m; total route 14.6 km between Kumkapı (Europe) and Koşuyolu, Kadıköy (Asia).
Turkey · 2011 – 2013 Structural and Tunnel Engineer Client: Yapı Merkezi
Details
Services
Analysis and design of primary and final lining in the NATM section, incl. intersections; design of cut-and-cover sections
Project phases
Detailed design
Himmelreich tunnel
Tunnel of about 1,045 m on the Hausmannstätten bypass (B73, Styria).
Austria · 2011 Structural Engineer Client: ASFINAG
Details
Services
Analysis and design of the tunnel cross-sections; formwork stripping analysis of the false ceiling (stripping time)
Project phases
Detailed design
Road tunnels T2 and T3, upgrade of RN43, Bejaia
Upgrade of a coastal road along a cliff: tunnels T1 (880 m), T2 (635 m), T3 (268 m) and escape tunnels E1 (137 m) and E2 (145 m), in heavily karstified limestone, block breccia and folded clay- and siltstone. Portals and alignment were optimised in option studies.
Algeria · 2008 – 2011 Tunnel Engineer Client: Özgün Construction
Details
Services
Analysis of the typical cross-sections
Project phases
Detailed design
A10 Tauern motorway, Tauern road tunnel
Twin-tube road tunnel of 6,546 m in the province of Salzburg, two lanes per tube.
Austria · 2008 – 2011 Structural and Geotechnical Engineer Client: ASFINAG
Details
Services
Analysis and design of the final lining, false ceiling and ventilation cavern; analysis and design of a retention dam
Project phases
Detailed design
Career
2023 – present
ARX Group SA, Zurich (Switzerland)
Senior Tunnel Engineer / Project Manager
2018 – 2023
Dr. Sauer & Partners GmbH, Salzburg (Austria)
Senior Tunnel Engineer / Project Manager
2008 – 2018
IGT GmbH, Salzburg (Austria)
Structural Engineer / Tunnel Engineer
Profile
More than 18 years of experience in tunnelling and underground construction, with projects in Europe, North and South America, the Middle East and North Africa, including the Semmering Base Tunnel, the Eurasia Tunnel in Istanbul, the Granitztal tunnel chain of the Koralm Railway and hydropower projects in Israel and Chile. Currently leads a team of five engineers and carries out independent checking of structural designs for SBB infrastructure projects.
Key skills
Design of complex underground structures
Underground works for hydropower: steel-lined pressure shaft, pressure tunnels, surge tank
Independent checking of structural designs (Category 3 check)
NATM, TBM, cut-and-cover
3D FEM and tunnel structural analysis
Risk management
Project management
Education
Dipl.-Ing. (MSc) Civil Engineering, 2008 TU Wien (Vienna University of Technology) Geotechnics and Construction Management
BSc Civil Engineering, 2001 Istanbul Technical University Concrete structures
Languages
Turkish: native
German: C2
English: C2
French: B1
Memberships
ÖGG – Austrian Society for Geomechanics
Publications
2023
P. Salak, O. Nathan, O. Koç, A. Pamsl French Hill Road Tunnels: A Pragmatic Rock Support Approach Proceedings of WTC 2023, Athens
2016
B. Kohlböck, O. Koç, T. Ayten Istanbul Strait Road Tube Crossing: Design of NATM Tunnels and Asian Transition Box Excavation Geomechanics and Tunnelling 9 (2016), No. 4, pp. 338–344
2013
O. Koç Strategies for Design of the Support Measures in Tunneling on Basis of Eurocode Proceedings of the 3rd International Symposium on Underground Excavations for Transportation, 29 Nov 2013, Istanbul
