V ifi ti f d t il f i ti t t Verification of details of existing structures Verification of details of existing structures with the elastic-plastic stress fields methodwith the elastic-plastic stress fields methodp

Author Galina ArgirovaEDCEENAC /Author Galina ArgirovaEDCE 2011/ENAC /EDCE/ENAC / Supervisor Prof A Muttoni/ENAC / Supervisor Prof. A. Muttoni/

OBJECTIVES:OBJECTIVES:

- To provide a simplified method for the analysis of - To study the effects of torsion warping and- To provide a simplified method for the analysis of - To study the effects of torsion, warping, andcritical details which will allow to take into distortion on the behavior of box-girder bridgescritical details which will allow to take into

t th f ll t ht f tidistortion on the behavior of box girder bridges.

account the full strenght of a section.account the full strenght of a section.T t d if th b ff t b t t d ith- To study if the above effects can be treated with

- To validate the elastic-plastic stress fields methody

the elastic plastic stress fields method- To validate the elastic-plastic stress fields method the elastic-plastic stress fields method.for critical details of bridgesfor critical details of bridges.

l f d l f h d l- To propose simplified rules for the rigid-plasticTo provide rules for the choice of the crack

To propose simplified rules for the rigid plastict fi ld th d f th ifi ti f th- To provide rules for the choice of the crack stress fields method for the verification of thep

inclination θ in an element and the coefficient kc webs of a box girders subjected to transverseinclination θ in an element and the coefficient kc webs of a box girders subjected to transverserepresenting the reduction of the concrete bending and shear forcesrepresenting the reduction of the concretet th d t ki

bending and shear forces.strength due to cracking.strength due to cracking.

KEYWORDS:KEYWORDS:Existing structures; Reinforced concrete bridges; Critical details; Shear transversal bending interaction; Analysis methods;Existing structures; Reinforced concrete bridges; Critical details; Shear transversal bending interaction; Analysis methods; Diaphragms; Support zone; Gerber articulationsDiaphragms; Support zone; Gerber articulations

TASKSTASKS:elastic-plastic stress field

1. Analyze with the elastic-plastic stress fieldselastic plastic stress field

1. Analyze with the elastic plastic stress fieldsth d d i id l ti t fi ld th d thmethod and rigid-plastic stress fields method theet od a d g d p ast c st ess e ds et od t e

results of existing tests of critical details such as:results of existing tests of critical details such as:g- zones with concentrated loads (prestressing- zones with concentrated loads (prestressing

force support reaction etc )force, support reaction, etc.)til ith d d d (f th i l ti- cantilevers with dapped ends (for the simulation

24 t dcantilevers with dapped ends (for the simulationof Gerber articulations)

24 strandsof Gerber articulations))

- diaphragms with indirect supports- diaphragms with indirect supports35 40

- nodes where compression struts and tension ties3035

25

40

45 nodes where compression struts and tension tiest

3035 25 25 454045505580

meetcrack inclination θ meetforce distribution in columns

crack inclination θ

- force distribution in columns- zones with insufficient anchorage of the tensile- zones with insufficient anchorage of the tensile

reinforcementreinforcement0.95 0 90

0.70 0.65 0.950.750.800.850.90

coefficient for the0.60

0 75

coefficient for the reduction of the

0.550.75 reduction of the

concrete strength kconcrete strength kc

3 Study the influence of transversal bending on2 Develop a sandwich element based on elastic- 3. Study the influence of transversal bending on2. Develop a sandwich element based on elastic-the resistance of webs of box girder bridges withplastic stress fields and validate it with results from the resistance of webs of box girder bridges witht i l di i d i S it l d

plastic stress fields and validate it with results fromi ti t t d t typical dimensions used in Switzerland.existing test data. ypg

element forces sectional forces layer stresseselement forces sectional forces layer stresses