In the context of the upgrading project of the existing Eastern Inner Ring Road of Thessaloniki, the construction of an Elevated Expressway (Flyover), next to the existing ring road (between I/C K5 and I/C K10) at an overlying level is suggested. The project will significantly decongest the existing ring road, which will also be upgraded to serve local and heavy traffic.
The entire project is extremely complex and technically demanding, judged as “Special and Important at National Level” planned to be constructed with a Public-Private Partnership Contract. METE SYSM has prepared the preliminary studies of the technical works for the whole project, which are already approved and participates in the preparation of the predesigns.
The most important and also special part of the project is the construction of an Elevated Bridge with a total length of 4.000m between I/C K6-Neapoli and I/C K8-Triandria. At the predesign stage, our office is responsible for the first section of this bridge (Bridge T9a) with a total length of 2.000m between I/C K6 and I/C K7, next to the existing Ring Road on the “Sheikh-Shu” forest side. In plan, the bridge alignment moves on straight lines along with circular arcs (R=1.100–1.200m) and corresponding transition curves. In elevation, the red line exceeds that of the adjacent ring road and the natural terrain usually by 7,0 – 8,0 m, but also 11,0 – 12,00 m, except for the areas of two valley bridges with red line elevation 25,0 – 30,0m above the ground.
The box-shaped cross-section is 2,5 m deep with a total width of 22,2 m, carrying bilateral traffic (2+2 lanes and emergency lanes). The net traffic width is 9,7m in each direction with an intermediate rigid safety barrier. At the two edges of the section, safety barriers, sound curtains and lighting poles are provided. The deck is also provided with insulation special membranes and a drainage system with longitudinal and vertical pipes.
Along the 2.000m of the bridge, a total of nine (9) independent substructures are formed, with lengths between 170,0m and 235,0m. The superstructures are continuous, with four to five spans of about 45,0 m and expansion joints at the ends of the subsections. The piers are single-column, of variable length, founded on shafts. The superstructure rests on bearings in the piers where expansion joints are provided and is monolithically connected to the rest of the piers, forming a case of semi-integral bridges.
Typology: Infrastructure
Road Viaducts G2
Road viaducts carrying two independent branches of motorway, with a total length of 350m, a width of 14,2m each, and a maximum pier height of 58m. Continuous superstructures of prestressed concrete single-cell box girder of variable depth, rigidly connected to the piers, constructed with the balanced cantilever method. Bridge piers are founded on cylindrical shafts.
Road Bridge G4
In the context of the upgrading of the Northern Crete Road Axis (BOAK), Bridge G4 from CH.5 + 710.99 to CH.6 + 150.00 (Gournes – Hersonissos section, Heraklion Prefecture) was recently constructed and delivered to traffic. METE SYSM prepared the final study of the project and provided support to the Contracting Consortium during its construction. After completion of the bridge, the construction company participated with it in the Concrete Awards 2019, the first awards created to highlight the excellence in concrete projects, in terms of design and construction level, but also functionality, originality, environmental protection, satisfaction of the end customers and users of these projects. Bridge G4 was distinguished by winning the silver award in the Infrastructure Works Section/Subsection: Bridges and Tunnels.
The bridge superstructure is continuous with five spans (total lengh 440,0m on the bridge axis) made of cast in-situ prestressed concrete. The balanced cantilever method was used for the construction with 3,5 to 5,0m long segments. A camber design study to support the contractor at every construction stage was also prepared.
In plan, the bridge alignment moves along a circular arc with a radius of 900m and a straight line after the corresponding transition curve. In elevation, the red line moves in a straight ascending section with a slope of 4,27%, at a height from the natural terrain, ranging from 5,0 to 31,0m, and mostly between 20,0 and 28,0m in the central part of the bridge. The clear heights of the piers are 15,0m, 20,5m and 22,0m . The outermost piers have a twin blade (rectangular) cross section while the central piers have a rectangular hollow section with external dimensions of 4,0×6,5 m. Piers are founded on pile caps.
The single box-shaped cross-section has a height which varies parabolically in elevation, ranging from 3,0m in the central span region to 6,5m in the pier supports. The total width is 13,75m carrying one-way traffic of the right branch of the highway with 2 traffic and 1 emergency lane and sidewalks on both edges. Safety barriers, street lighting poles, insulation of the deck with a special membrane and drainage of the deck with longitudinal and vertical drainage pipes are also provided.
The superstructure is monolithically connected to the four piers, resting on sliding bearings (vertical) along with shear keys (transverse horizontal) at the abutments, forming a case of semi-integral bridge with satisfactory behavior for both vertical as well as horizontal loads, with expansion joints and bearings only at the abutments and with reasonable displacements.