The Riga Central Station project is part of a larger railway project that will integrate the Baltic States into the European rail network. The project consists of design and construction of the station building, railway infrastructure, road infrastructure and their integration into the city of Riga. The geographical boundary of the project is the existing railway infrastructure and adjacent infrastructure from Jelgavas Street to Lāčplēša Street.

The project aims to transform Riga Central Passenger Station into a Rail Baltica multimodal public transport hub, integrating the Rail Baltica railway line with the 1520 mm railway track infrastructure, road transport, metropolitan transport and passenger and cyclist flows.

The implementation of the Rail Baltica project at the Central Station includes the construction of 1435 mm passenger rail tracks within the project limits. During the project implementation, the operation of the Central Station on the existing 1520 mm rail connections to Torņakalns, Zemitāni, Jāņavārti, Šķirotava and Vagonu Parks stations shall be maintained.

Within the framework of the project, "Ceļuprojekts" is carrying out the design and supervision of all street reconstruction works, the construction of the new 1435 mm railway overpass over Lāčplēša Street, the reconstruction and widening of the existing Dzirnavu Street overpass. The project is the first in Latvia to apply BIM technologies to infrastructure projects, which allows for easy, transparent and efficient coordination of solutions for individual parts of the construction project in a complex and challenging urban project.

Geotechnical investigations for the construction project were carried out by the Geology department of "Ceļuprojekts" from October 2019 to July 2020. The works included geotechnical drilling (with quality class 1-2 sampling according to EN 22475-1) at 51 points to a depth of 30...50m, static probing with pore water pressure measurements (CPTu) at 111 points, flat dilatometer tests (Marchetti DMT) at 9 points and pressuremeter tests at 18 boreholes with measurements at 309 depth intervals. In addition, groundwater and groundwater level observation/monitoring boreholes (piezometers) were installed between 7 and 42 m deep at 12 locations.

The geotechnical investigations were carried out in difficult conditions, including on the platforms and tracks of the Central Station, in pedestrian tunnels, on streets with high traffic intensity, as well as in the Daugava River from a floating platform (in cooperation with SIA Totas and SIA VKB). The drilling works were carried out using a large drilling rig URB-2A2 and a small drilling rig Geomash MBU224, and in difficult access areas small drilling rigs on tracked chassis were used - Beretta T41, L&K Bohrtechnik KB-20 and KB-10. Static probing and flat dilatometer tests were performed with a multifunctional probing rig Geotech 220-4 (with a pressure capacity of 20 tonnes).

The geotechnical laboratory of "Ceļuprojekts" tested a total of 866 samples for mechanical parameters, i.e. deformation modulus (oedometer test), shear resistance, bond and internal friction angle (direct shear test and triaxial test), uniaxial compressive strength, as well as for physical parameters, i.e. granulometric composition, water content, Atterberg limits, organic content and groundwater chemistry.

"This international mega-project with Design&Build specificity has provided the company with valuable experience in working with foreign partners and has given the company's team the opportunity to perform BIMisation of the design process," says Mārtiņš Taurenis, project manager for JSC "Ceļuprojekts". "This project provides an opportunity to shape the city's infrastructure for decades to come. We treat this opportunity with respect and consider several possible solutions for each complex junction. Of course, in an urban environment, compromises have to be made, but that is the special job of an engineer - to find the best solution for the given conditions," adds Toms Polovinkins, the project's chief road engineer.