Slab Deflection Analysis
Objective: Check of the slab 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. 139-140.
Initial data file:
Example 57.SAV
report – Arbat 57.doc.
Compliance with the codes: SNiP 2.03.01-84*.
Initial data:
|
l= 3,1 m |
Пролет плиты |
| b×h = 1000×120 mm | Размеры сечения плиты |
| а = 15 mm | Расстояние от центра тяжести арматуры до сжатого края сечения |
| As = 393 mm2 (5Ø10) | Площадь сечения арматуры |
| qtot = 7 kN/m | Полная равномерно распределенная нагрузка |
| ql = 6 kN/m | Часть полной равномерно распределенной нагрузки от постоянных и длительных нагрузок |
|
Concrete class |
В25 |
ARBAT initial data:
Importance factor γn = 1
Importance factor (serviceability limit state) = 1
Structure:
Section:
|
b = 1000 mm h = 120 mm a1 = 10 mm a2 = 10 mm
|
|
|---|
|
Reinforcement |
Class |
Service factor |
|
Longitudinal |
A-II |
1 |
|
Transverse |
A-I |
1 |
Specified reinforcement:
|
Span |
Segment |
Length (m) |
Reinforcement |
Section |
|
span 1 |
1 |
3.1 |
S1 - 5Ø10
|
|
Concrete:
Concrete type: Heavy-weight
Concrete class: B25
Density of concrete 2,5 T/m3
|
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 |
12,1 mm |
|
ARBAT |
12,839 mm |
|
Deviation, % |
5,8 % |
Comment: The difference in the results is due to the fact that approximate empirical formulas are used in the Guide.