The conference participants can choose from five site visits to the underground structures in and around Prague organised on Wednesday morning, 27 May 2026.
- Site visit A – Prague Metro Line D — construction of the Pankrác—Olbrachtova section
The maximum number of participants for Site Visit A is 60. - Site visit B – Main traffic control centre of the city of Prague
The maximum number of participants for Site Visit B is 20. - Site Visit C – Rudolf adit + Old wastewater treatment plant
The maximum number of participants for Site Visit C is 20. - Site visit D – Construction of tunnels on the D11 motorway and on the Náchod bypass
The maximum number of participants for Site Visit D is 20. - Site visit E – Exploration adit for the Kamenná vrata Tunnel and Pepr mine workings
The maximum number of participants for Site Visit E is 20.
Application for the Site Visit
If you intend to participate in an excursion, please indicate your selected option when completing the online registration form.
Given the limited capacity, early registration is advised.
English interpretation of all excursions will be provided for foreign participants.
Site visit A – Prague Metro Line D — construction of the Pankrác—Olbrachtova section
The construction of Prague Metro Line D commenced with the I.D1a section Pankrác— Olbrachtova, including a track connection to the existing Line C and a transfer to the current Pankrác C station. In 2026, the excavation of the Pankrác D station will be nearing completion, followed by the casting of secondary linings and the realization of internal structures.
Pankrác D is designed as a single-vault mined station with three escalator tunnels. The station facilities include two secant pile shafts, access and ventilation adits, a ventilation plant room, a disassembly chamber, and a reversing track tunnel.
The inter-station section comprises shafts, a ventilation plant room, a double-track tunnel, single-track tunnels, a stabling tunnel, and the C-D track connection linking the existing Line C with the new Line D, including tunnel bifurcations.
Olbrachtova station is designed as a double-vault mined station located on a curve, featuring two escalator tunnels. The station also includes a cut-and-cover shaft, cross-passages, and a technological tunnel.
Excursion participants will have the opportunity to inspect most of the underground sections of this project.
Site visit B – Main traffic control centre of the city of Prague
UTCC Prague is the competent control centre for traffic in road tunnels in the central part of Prague and is the highest level of the telematic transport system operated in the City of Prague. UTCC is currently located in the building of the Central Dispatching building for public transport, in Prague 2. It is operated by officers of the Police of the Czech Republic. This specialized facility also collects and processes transport information on traffic in the delineated section or area of the road network, transport data from telematic applications in the various sensor cross-sections, technological information on the state of operation of various pieces of equipment and warning alerts on critical situations.
The excursion will focus on a tour of the dispatching centre and information concerning the monitoring and management of traffic in tunnels in the central part of Prague.
Site Visit C – Rudolf adit + Old wastewater treatment plant
The Rudolph Adit is a 1102 m long historical underground work. It has an oval profile, with a height ranging from 2 to 4 metres and a width of 80 to 150 cm. The average temperature inside is around 11 degrees. The route of the tunnel leads around 45 m below ground level.
The adit, which from the beginning served to connect the ponds in the Royal Game Reserve to water from the Vltava, was built in 1584–1593 on the orders of Emperor Rudolph II. Construction of the adit was entrusted to the chief bergmeister Lazar Ercker von Schreckenfels, who was helped by chief mine surveyor Jiří Oeder of Ústí.
Completion of work on the adit was managed by Ercker’s successor Van der Vam Kojas. The whole work cost 66299 threescores of Groschen. Where the rock was not firm enough, the corridors were reinforced only with timber. In the years 1636–1639 the adit was bricked by the portals, and later to a greater extent as well. In 1711 a wooden boardwalk was built along its whole length. Over its existence, the walls of the adit have collapsed inside many times and the corridor thus had to be cleared out. In the 1950s the bottom of the tunnel was tiled with gutters.
The old wastewater treatment plant in Prague – Bubeneč is an important document in the history of architecture, engineering and water management. It was built in the years 1901–1905 as the last link in the systematic sewer network in Prague. It served to treat the majority of wastewater in Prague up until 1967, when the Central Wastewater Treatment Plant was put into operation on the nearby Císařský ostrov. The project for the sewer system and design of the technical parameters for the plant were drafted by the civil engineer of British origin Sir William Heerlein Lindley.
Site visit D – Construction of tunnels on the D11 motorway and on the Náchod bypass
Construction of tunnels on the D11 motorway
In September 2025, construction began on the 0.5 km long Opevnění motorway tunnel. Together with the subsequently constructed Poříčí Tunnel, it will be one of the most technically demanding structures on the border section of the D11 motorway between the Czech Republic and Poland. In addition to these two underground structures, this 21.175 km long section of the D11 motorway is notable in particular for its 28 bridge structures, including several exceptionally complex and long viaducts.
The Poříčí Tunnel consists of two tubes for one-way traffic: the left tube is 540 m long and the right tube 576 m long. The tubes are interconnected by two mined cross passages. The Opevnění Tunnel has two tubes of equal length (492 m), with one mined cross passage designed at the midpoint. Both tunnels are designed in the T-8.0 width category, with both horizontal and vertical curvature. The clearance height is 4.8 m. The Poříčí Tunnel is designed in safety category TC, while the Opevnění Tunnel is in category TB. The design speed is 100 km/h. The distance between the two tunnels is approximately 4.5 km.
The Poříčí Tunnel is named after the Poříčí Ridge through which it passes, while the Opevnění Tunnel is named after the long belt of former military infantry bunkers located in its immediate vicinity.
Given the relatively favourable overburden height and the quality of the rock mass, the New Austrian Tunnelling Method (NATM) is proposed for tunnel excavation, with horizontal face division and technological excavation classes (TEC) 3, 4 and 5a. The excavation cross-section reaches an area of 90 m². The secondary lining is designed as a double-shell structure founded on strip footings, with an intermediate umbrella-type membrane waterproofing. Under the most favourable geotechnical conditions, an unreinforced secondary lining with a thickness of 300 mm at the crown is proposed. Cut-and-cover tunnel sections at the portals are constructed in open, sloped excavations secured by soil nailing. After completion, they will be largely backfilled.
Construction of tunnels on the Náchod bypass
On the 6.5 km route of the I/33 Náchod bypass, whose purpose is to relieve transit traffic load mainly in the centre of the town of Náchod, there are 14 bridges and two road tunnels. The first tunnel on the route from the direction of Vysokov is the prefabricated cut-and-cover Kramolna Tunnel, and at approximately km 3.8 the portal of the mined Dolní Radechová Tunnel is located. The tunnels are named after the municipalities near which they are situated.
The Kramolna Tunnel is a single-tube tunnel of category T-9.5 with two-way traffic and a length of 100 m. The main reason for designing the Kramolna Tunnel on the route of road I/33 is the need to pass through a geomorphologically pronounced short ridge, or rather a saddle, south of the village of Kramolna. The highest point of the terrain reaches approximately 448 m above sea level, while the road alignment at this location has a vertical level of 435 m above sea level. The highest point of the terrain reaches an elevation of approximately 448 m a.s.l., while the road alignment at this location has a finished grade level of 435 m a.s.l. The south-western portal (km 1.840) is situated on a slope below the saddle within an allotment garden area, with the alignment reaching it via a cut-and-fill section in the undulating hillside. The commencement of the construction pit excavation is scheduled for the turn of 2025/2026.
The Dolní Radechová Tunnel is also a single-tube tunnel of category T-9.5 with two-way traffic, situated in the south-western part of the village of Dolní Radechová. The total length of the tunnel is 363 m and it is divided into three cut-and-cover sections with a construction pit in the central part of the tunnel, and two mined sections. The first mined section is 164.30 m long and the second 133.0 m long. In the central cut-and-cover section of the tunnel, an emergency escape gallery is designed perpendicular to the tunnel, with its portal located near the Dolní Radechová cemetery. Along the alignment of the mined tunnel, Permian rocks occur—arkosic sandstones, conglomerates and breccias—with a variable degree of weathering and tectonic disturbance. At the portal areas and in the central part of the tunnel, Quaternary and eluvial soils intrude into the profile, influencing the design of excavation support stability; therefore, for technological class TT4P, the possibility of closing the profile with an invert arch is considered.
The mined tunnel is constructed using the NATM, divided into technological classes TT2 to TT4, or TT4P at the four portals. The tunnel lining is designed from sprayed concrete SB30 (C25/30 – X0) with a thickness of 200 to 250 mm depending on the technological class, three-element lattice girders with two layers of reinforcing welded mesh KARI 8×150×150 mm. The excavation cross-sectional area in class TT4 without an invert arch is 102.3 m². Excavation of the tunnel commenced on 16 October 2025.
Site visit E – Exploration adit for the Kamenná vrata Tunnel and Pepr mine workings
The objective of the exploratory adit is to clarify the geotechnical conditions prior to the construction of the Kamenná Vrata Tunnel on the D3 motorway. The excavation of the exploratory adit is being carried out downhill (downgradient) from the construction pit in hard rock using blasting operations. The New Austrian Tunnelling Method (NATM) is being employed for the construction. The total length of the adit will be approximately 1.6 km, with a width at the invert of approximately 3.0 m and a height of approximately 3.7 m. The adit also includes passing bays.
Furthermore, the excursion includes a visit to the nearby mining museum located at the Pepř gold mine. The route within the Pepř mine is 4 km long and includes a ride on a mine train. Gold mining in the Jílové region has a very long tradition, with underground mining dating back to approximately the 13th century. In the mid-20th century, the main mining activities, including the subsequent processing of the gold ore, were concentrated at the Pepř mine, which served as the centre of the district. The excursion includes the historic Václav adit, where visitors can enjoy an authentic gold mining experience. In the Šlojíř vein, it is possible to see massive stoped-out areas where rich gold ore was once located, as well as unmined pillars with gold mineralisation. Underground, you will see functional mining machinery and a gold-bearing ore vein. More detailed information is available at www.jilovskezlatedoly.cz.