The bridge checks as described in EN 1992-2 (Eurocode 2, Part 2) are designed to supplement the 3D FEM analysis. They can be used for bridges and other engineering constructions in which actions from street or railway traffic according to EN 1991-2 (Eurocode 1, Part 2) have to be taken into account. Permitted structure models include beam, area and solid structures. In detail the following standards are considered:
- EN 1992-2 as the base document
- OENORM EN 1992-2 with the National Annex Austria
- DIN EN 1992-2 with the National Annex Germany. The optional inputs for checks according to the guideline for the recalculation of existing road bridges (recalculation guideline) are separately indicated in the text.
Actions, Design Situations
The actions according to EN 1991-2 are simply mapped to the load cases by the user. The program then automatically creates the decisive design values for the ultimate limit state and serviceability limit state while considering the safety factors and combination coefficients. For each combination different design situations can be defined for the construction and end states. When conducting the check, the extreme value deriving from all combinations and situations applies.
Checks at the ultimate limit state
- Minimum reinforcement against failure without warning
- Bending with or without normal force or normal force only
- Lateral force under consideration of the minimum level of reinforcement
- Pure torsion and torsion with lateral force
Checks against fatigue
- Fatigue of longitudinal reinforcement and tendons
- Fatigue of lateral force reinforcement and torsional reinforcement
- Fatigue of concrete under longitudinal compressive stress
- Fatigue of the concrete struts under lateral force and torsion
Checks at the serviceability limit state
- Limiting the concrete compressive stresses
- Limiting the reinforcing steel stresses
- Limiting the prestressing steel stresses
- Minimum reinforcement for the crack width limitation
- Limiting the crack width via direct calculation
- Decompression check
- Limiting deformations
- Check of the inclined main tensile stresses
Ultimate Limit State and Fatigue
The dimensioning of the reinforcement is performed separately on a per checks basis for the modeled design situations. This is determined individually for each combination of internal forces. The final result is derived from the extreme value of all calculated reinforcements.
If required, the checks are carried out in state II under consideration of the calculated maximum reinforcement. In order to attain the required crack width, the minimum reinforcement is increased, if necessary.
The following table demonstrates how the situations are used in the various checks. The numbers refer to the chapters of the standards.
|Situation||Load-Bearing Capacity||EN 1992-1-1||EN 1992-2|
|Permanent & temp.
|Situation||Serviceability||EN 1992-1-1||EN 1992-2|
|Concrete compressive stresses
Reinforcing steel stresses
Concrete compressive stresses
|Frequent||Decompression, class XC2-XS3
Crack width, prestressing with bond
|Quasi-permanent||Concrete compressive stresses
Crack width, reinforced concrete & prestressing without bond
The calculated reinforcement can be output graphically (contours, color gradient, section or numerically) or in table form. This can be selected either for individual checks or for the entire reinforcement. The checks are documented in a detailed log.