Girder Deflection Analysis
Objective: Check of the girder deflection analysis
Task: Verify the correctness of the deflection calculation
References: Guide on designing of concrete and reinforced concrete structures made of heavy-weight or lightweight concrete (no prestressing) (to SNiP 2.03.01-84), 1989, p. 140.
Initial data file:
Example 58.SAV
report – Arbat 58.doc.
Compliance with the codes: SNiP 2.03.01-84*.
Initial data:
| l = 4,8 m | Girder span |
| b×h = 200×600 mm | Girder section sizes |
| а = 80 mm | Distance from the center of gravity of the reinforcement to the compressed edge of the section |
| As = 2463 mm2 (4Ø28) | Cross-sectional area of reinforcement |
| qtot = 85,5 kN/m | Total uniformly distributed load |
| ql = 64 kN/m | Part of the total uniformly distributed load from permanent and long-term loads |
| Concrete class | В25 |
| Class of reinforcement | А-III |
Deflection is limited by aesthetic requirements.
ARBAT initial data:
Importance factor γn = 1
Structure:
Section:
|
h = 600 mm a1 = 66 mm a2 = 20 mm |
|
|
Reinforcement |
Class |
Service factor |
|
Longitudinal |
A-III |
1 |
|
Transverse |
A-I |
1 |
Specified reinforcement:
|
Span |
Segment |
Length (m) |
Reinforcement |
Section |
|
span 1 |
1 |
4.8 |
S1 - 4∅28 |
|
Concrete:
Concrete type: Heavy-weight
Concrete class: B25
Density of concrete 2,5 T/m3
Hardening conditions: In steam-curing chambers
Hardening factor 1
|
Service factor for concrete |
||
|---|---|---|
|
γb2 |
allowance for the sustained loads |
1 |
|
|
resulting factor without γb2 |
1 |
Conditions of operation:
Mode of concrete humidity - Natural humidity
Humidity of environmental air - 40-75%
Comparison of solutions:
|
Check |
maximum deflection |
|
Guide |
19,7 mm |
|
ARBAT |
20,298 mm |
|
Deviation, % |
3,4 % |
Comment: Since the deflection is limited by aesthetic requirements, the load was taken as ql=64 kN/m (see Sec. 1.17 of the Guide).