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X2
Category 2: Civil Structures
The bridge over the Danube-Black Sea Channel from
Agigea - km 0 + 540 - is located at the confluence of the
Black Sea and the Channel, near Constanta seaport.
The bridge ensures the connection between the Northern
and Southern zones of the harbour, now separated by
the Danube-Black Sea navigable canal. The structural
engineers from Search Corporation SRL are using Allplan
Engineering to carry out this special project.
The bridge and access viaducts have a total length of
906.82 m, with 362.00 m for the bridge and 544.82 m for
the viaducts.
The overpass of the Danube-Black Channel is carried
out with a cable-stayed bridge which has three spans of
81.40 m and 200.00 m + 81.40 m; the superstructure has
a total length of 362.80 m.
The deck of the cable-stayed bridge is made from a
composite structure (steel + concrete), partly made of
prestressed concrete on the lateral spans, and metal,
partly in collaboration with the flooring from the reinforced
concrete of the bridge superstructure. The access viaduct
decks are made from prestressed, precast, reinforced
concrete beams, which works through a monolithic plate
and prestressed concrete cross pieces.
Above the anchorage area, the pillars are made from
composite sections: steel box (where the anchorages of
the cables are positioned) embedded in concrete. The
cooperation is achieved with flexible connectors welded to
the steel box of the anchorages. The total height of these
pillars is 62.00 m.
The design elements for the bridge over the canal and
viaducts, as required by the specifications and project
are:
• The clear height under the bridge should be equal to
the railway bridge from the lock, which is 17.70 m and
provides the navigation gauge required for the Danube-
Black Sea Channel which has a height of 17.50 m, a
width of 35.00 m in the middle of the waterway and
10.00 m on the remaining width.
This is required by both technical and economic
conditions and also for ensuring the safety zones,
protection and stability of the channel section;
• The bridge is equipped with a roadway width of
14.80 m, which provides four lanes: two lanes for traffic
and two lateral pedestrian sidewalks with a minimum
width of 75 cm;
• A life-time of at least 50 years, designed according to
norm AND 554-2002;
• The structural strength of the bridge over the canal
and the access viaducts is designed for live loads
according to STAS 3221-86 “Bridges Road. Convoy
type and class loading”;
• In terms of the seismic design, the work is placed
according to norm SR-EN 1998-2:2006 and National
Annex SR-EN 1998-2: 2006/NA: 2010.
In the cross-section, the bridge superstructure is made
from two steel box coffered girders in collaboration
with reinforced concrete flooring, respectively from two
prestressed concrete coffered beams.
The solution adopted for the execution of the bridge is
characterised by the modern design structure, which
presents a number of technical and economic advantages
such as:
• Combination of relatively simple structural components
with known technologies in a unitary complex structure;
• Reducing the duration of construction, with all the
benefits arising from achieving this goal;
• Achieving a work with a particular architectural aspect;
• Achieving a work with a height of reduced construction,
of only 3.05 m, representing approximately L / 70 of the
central span of the bridge, L = 200 m.
Workflow with Allplan Engineer
The design started with the generation of the digital model
of the terrain using the specific functions from Allplan
(Digital Terrain model).
The road and the deck elements were created using the
Bridge/Civil Engineering module.
The general arrangement drawing files were realised
directly from 3D using the Associative Views module.
Because of the reinforcement complexity, the
reinforcement model had to be checked for every inserted
placement of bars. Using the function Collision check
and displaying bars with different surface colours, the
structural engineers did this more efficiently.
Special 3D objects and textures were used for obtaining a
realistic presentation.
Bridge over the Danube - Agigea Constanta, Romania
Software: Allplan Engineering
