Construction of new Railway Bridges over the Gallikos River, at CH. 9+184 of the Railway Line, on the section from Plati Railway Station to T.C.1 Thessaloniki

Description

Construction of the two (2) new railway bridges (up and down lines), at CH. 9+184 of the Thessaloniki – Florina line, which are to replace the existing steel bridges. The project includes: The dismantling of the two independent branches of the existing bridge and of their piers in two phases The engineering works for the improvement of the foundation ground and the necessary retaining structures, in order to prevent liquefaction of the soils during foundation excavations, riverbed diversions, etc. The engineering works for the construction of the two (2) new concrete bridges, one for each of the Up and Down lines, with a total length of: 175.50 + 175.50 = 351.00 m. The railway component of the track laying on the new railway bridges, with a total length of 700 m, which, beyond the length of the two bridges, includes their transition sections. The hydraulic works for the shaping of the bed of the Gallikos River, as well as the hydraulic works for the diversion of the bed, across the entire area occupied by the railway bridge construction works and in particular at the positions of their foundations. The works for the dismantling of the existing electrification network, along the length of the existing network zones. The works for the installation of the new electrification network, in the corresponding network zones, on the Up and Down railway lines. The works for the dismantling of the GSMR and ETCS installations (supports, cables, etc.), their temporary suspension during the construction phase and their reinstallation at the new positions. The railway works required to maintain the operation of the existing railway line (on the single branch during the construction works phase – Up or Down) so that electrified railway traffic is maintained during all construction phases of the project, on the Thessaloniki – Florina line. The works required for the adaptation of the signalling equipment located in the area affected by the construction works, ensuring the continuous operation of the OSE telecommunications network, of the signalling system of Sindos Railway Station, of the Sindos and TC1 block section, as well as of the Thessaloniki – Florina remote control, so that Sindos and TC1 stations can set routes towards each other and open the exit signals during construction. The works for the construction – reinstatement of the existing road network serving local vehicle traffic. The new bridge has a total of 13 spans, with the intermediate piers positioned between the existing ones. The total length of the bridge is 175.50 m (from the abutment joint A1 to the abutment joint A2) and it is divided into three sections (with expansion joints). This results in two four-span decks and one five-span deck. Each deck is monolithically connected to the intermediate piers at the middle supports and rests on bearings at the end supports. A continuous reinforced concrete slab is constructed with spans of 12.75 m – 14.00 m. The cross-section of the superstructure is a slab with circular voids of 0.50 m, so as to limit the dead load of the structure.