4-Lecture 2a - October 1st, 2013

8/13/2019 4-Lecture 2a - October 1st, 2013

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STR654Inspection, Repair, and

Maintenance of Steel StructuresLecture 2a, October 1st, 2013

Sherif A. Mourad

Professor of Steel Structures and Bridges

Faculty of Engineering,

Cairo University


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TOPICS

Responsibility of each party.Shop Fabrication.

Dimensional tolerance in

fabrication.


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Parties Involved Owner

Designer

Contractor: Fabricator.

Erector. Site supervisor.

Third-Party Inspector.


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Design Responsibility

Owner-Designer-Contractor: Designer to provide design & specs. Contractor to check & advise

problems.

Contractor to build.

Owner-Contractor: Contractor to design and build.


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SHOP FABRICATIONIdentification of material.

Preparation of material.Fitting and fastening.

Fabrication tolerance.

Shop cleaning and painting.Marking and shipping.


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REFERENCE CODE

Egyptian Code of Practice for SteelConstruction and Bridges. Code

No. 205, Ministerial decree 279-

2001.Chapter 12: Dimensional Tolerance.

Chapter 13: Fabrication, Erectionand Finishing Works.


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IDENTIFICATION OF

MATERIALS

Mill certificate.

Additional testing.Identify materials ordered to

special requirements


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PREPARATION OF

MATERIALS

Thermal cutting:

Hand guided.Mechanically-guided

Achieving specified roughnessheight.


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FITTING AND FASTENING

Welding.

Backing bars/tab clean-up.Weld inspection.

Trial fitting of assembly.


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FABRICATION TOLERANCE

Deflection of column between

points which will be laterally

restrained on completion of

erection.

fh1=

0.001 h11.fh1= 0.002 h11 for hollow X-sec.


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Deflection of column between

floor slabs.

fh=

0.001 h1.fh= 0.002 h1 for hollow X-sec.


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Lateral deflection of compression

flange of girder, relative to the weakaxis, between points which will be

laterally restrained on completion oferection

f11= 0.001 lb.

f11

= 0.002 lb

for hollow X-sec.


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Lateral deflection of girder

f1= 0.001 lb.

f1= 0.002 lb for hollow X-sec.


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Maximum bow of web for girders

and columns (depth of web hw,

width of flange b)

fw= hw/150


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Inclination of web between upper

and lower flanges

vw= hw/75


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Eccentricity of the web in

relation to the center of either

flange.

vw1= b/40 10 mm


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Position deviation of parts

connected to a girder or column,

e.g., cover plate, base plate etc.

e1= 7 mm in any direction.


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Position deviation of end plates of

girders.

e1= 5 mm in any direction.


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Length of prefabricated

components to be fitted between

other components.

lt, hc= + 0 or 5 mm.


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FABRICATION TOLERANCE Maximum bow of web for

plate girders with intermediatestiffeners (depth of web d,

thickness of web tw).

fw= (least of d or d1)/115

for d/tw


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Flanges of plate girders.

C/250 6 mm.


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Unevenness of plates in thecase of contact bearing surfaces:

One mm over a gauge length of300 mm.

4-Lecture 2a - October 1st, 2013

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