Calculation of a Rib of a TT-shaped Floor Slab for Load-bearing Capacity under Lateral Forces
Objective: Check the mode for calculating reinforced concrete structures in the “Reinforced Concrete” postprocessor of SCAD
Task: Verify the correctness of the strength analysis of oblique sections and a concrete strip between the oblique sections.
References: Guide on designing of concrete and reinforced concrete structures made of heavy-weight concrete (no prestressing) (to SP 52-101-2003), 2005, p. 56-57.
Initial data file:
| when the lateral force is Q = 62 kN – | SCAD 12.1.SP. spr |
| report – | SCAD 12.1.SP.doc. |
| when the lateral force is Q = 58,4 kN – | SCAD 12.2.SP. spr |
| report – | SCAD 12.2.SP.doc. |
Compliance with the codes: SP 52-101-2003, SP 63.13330.2012.
Initial data:
| b×h = 85×350 mm | Section sizes |
| а = 35 mm | Distance to the c.o.g. of tensile reinforcement |
| d = 8 mm | Diameter of transverse reinforcement |
| s = 100 mm | Spacing of transverse reinforcement |
| q = 21,9 kN/m | Load on the rib |
| q = 18 kN/m | Temporary equivalent load |
| Q = 62 kN | Lateral force on the support |
| Concrete class В15 | |
| Class of transverse reinforcement А400 |
Results of the SCAD analysis (when the lateral force is Q = 62 kN):
|
N Max. 0 kN
Max. 0 kN |
My Max. 0 kN*m Max. 48,18 kN*m |
Mz
|
|
Mk
|
Qz Max. 62 kN
Max. -62 kN |
Qy
|
|
|
Length of the bar 3,11 m |
|
Structural group Beam
Number of rebars in a row must be not less than two (see Sec. 8.3.7 of SP 52-101-2003)
Distance between the rebars in the first row S1 is less than the allowable value (see Sec. 8.3.3 of SP 52-101-2003) .
Elements: 1
Importance factor γn = 1
Member type - Flexural
Stress state - Uniaxial bending
|
Coefficients allowing for seismic action |
|
|---|---|
|
Normal sections |
0 |
|
Oblique sections |
0 |
|
Distance to the c.o.g. of reinforcement |
|
|---|---|
|
a1 |
a2 |
|
mm |
mm |
|
32 |
32 |
|
Reinforcement |
Class |
Service factor |
|---|---|---|
|
Longitudinal |
A400 |
1 |
|
Transverse |
A400 |
1 |
Concrete
Concrete type: Heavy-weight
Concrete class: B15
|
Service factor for concrete |
||
|---|---|---|
|
γb1 |
allowance for the sustained loads |
1 |
|
γb2 |
allowance for the failure behavior |
1 |
|
γb3 |
allowance for the vertical position during concreting |
1 |
|
γb4 |
allowance for the freezing/thawing and negative temperatures |
1 |
Humidity of environmental air - 40-75%
Crack resistance
No cracks
Structural group Beam. Element No. 1
Member length 3,11 m
Specified reinforcement
|
Segment |
Reinforcement |
Section |
|---|---|---|
|
1 |
S1 - 2Ø6
|
|
|
Results |
|||
|---|---|---|---|
|
Segment |
Utilization factor |
Check |
Checked according to SNiP |
|
1 |
0,9 |
Strength in a concrete strip between oblique sections |
Sec. 6.2.33, Sec. 3.52 of the Guide |
Comparison of solutions
|
Check |
Strength in a concrete strip between oblique sections |
|
Guide |
62/68,276 = 0,908 |
|
SCAD |
0,9 |
|
Deviation, % |
0,9 % |
Results of the SCAD analysis (when the lateral force is Q = 58,4 kN):
|
N Max. 0 kN
Max. 0 kN |
My Max. 0 kN*m
Max. 42,74 kN*m |
Mz
|
|
Mk
|
Qz Max. 58,4 kN
Max. -58,4 kN |
Qy
|
|
|
Length of the bar 2,93 m |
|
Structural group Beam
Number of rebars in a row must be not less than two (see Sec. 8.3.7 of SP 52-101-2003)
Distance between the rebars in the first row S1 is less than the allowable value (see Sec. 8.3.3 of SP 52-101-2003) .
Elements: 1
Importance factor γn = 1
Member type - Flexural
Stress state - Uniaxial bending
|
Coefficients allowing for seismic action |
|
|---|---|
|
Normal sections |
0 |
|
Oblique sections |
0 |
|
Distance to the c.o.g. of reinforcement |
|
|---|---|
|
a1 |
a2 |
|
mm |
mm |
|
32 |
32 |
|
Reinforcement |
Class |
Service factor |
|---|---|---|
|
Longitudinal |
A400 |
1 |
|
Transverse |
A400 |
1 |
Concrete
Concrete type: Heavy-weight
Concrete class: B15
|
Service factor for concrete |
||
|---|---|---|
|
γb1 |
allowance for the sustained loads |
1 |
|
γb2 |
allowance for the failure behavior |
1 |
|
γb3 |
allowance for the vertical position during concreting |
1 |
|
γb4 |
allowance for the freezing/thawing and negative temperatures |
1 |
Humidity of environmental air - 40-75%
Crack resistance
No cracks
Structural group Beam. Element No. 1
Member length 2,93 m
Specified reinforcement
|
Segment |
Reinforcement |
Section |
|
1 |
S1 - 2Ø6 Transverse reinforcement along the Z axis 1Ø8, spacing of transverse reinforcement 100 mm
|
|
|
Results |
|||
|---|---|---|---|
|
Segment |
Utilization factor |
Check |
Checked according to SNiP |
|
1 |
0,9 |
Strength for an oblique section |
Sec. 6.2.34, Sec. 3.52,3.71 of the Guide |
Comparison of solutions:
|
Check |
Strength for an oblique section |
|
Guide |
58,4/63,97 = 0,913 |
|
SCAD |
0,9 |
|
Deviation, % |
1,4 % |