Calculation of a Simply Supported Rectangular Beam under Lateral Forces

Objective: Check the mode for calculating reinforced concrete structures in the “Reinforced Concrete” postprocessor of SCAD

Task: Check the strength of the oblique section of the beam for the specified reinforcement

References: Guide on designing of concrete and reinforced concrete structures made of heavy-weight concrete (no prestressing) (to SP 52-101-2003), 2005, p. 57-58.

Initial data file:

SCAD 13 SP.spr
report – SCAD 13 SP.doc

Compliance with the codes: SP 52-101-2003.

Initial data:

b×h = 200×400 mm	Section sizes
а = 30 mm	Distance to the c.o.g. of tensile reinforcement
а/= 30 mm	Distance to the c.o.g. of compressed reinforcement
Asw = 101mm2 (2Ø8)Класс бетона В25	Cross-sectional area of transverse reinforcement
sw = 150 mm	Spacing of transverse reinforcement
qv = 36 kN/m	Temporary load on the beam
qg = 14 kN/m	Permanent load on the beam
Q = 100,35 kNm	Lateral force on the support
Concrete class В25
Class of reinforcement 240

 

Results of the SCAD analysis:

N Max. 0 kN Snap 0 m Max. 0 kN Snap 0 m	My Max. 0 kN*m Snap 0 m Max. 100,7 kN*m Snap 2,01 m	Mz
Mk	Qz Max. 100,35 kN Snap 0 m Max. -100,35 kN Snap 4,01 m	Qy
	Length of the bar 4,01 m Length of the flexible part 4,01 m Loading L1 - "50 kN/m"

 

Structural group Beam

Structural group Beam. Element No. 1
Importance factor γ_n = 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
30	30

 

Reinforcement	Class	Service factor
Longitudinal	A240	1
Transverse	A240	1

 

Concrete
Concrete type: Heavy-weight
Concrete class: B25

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 4,01 m

Specified reinforcement

Segment	Reinforcement	Section
1	S1 - 2Ø6 S2 - 2Ø6 Transverse reinforcement along the Z axis 2Ø8, spacing of transverse reinforcement 150 mm Transverse reinforcement along the Y axis 2Ø8, spacing of transverse reinforcement 150 mm

 

Results
Segment	Utilization factor	Check	Checked according to SNiP
1	0,98	Strength for an oblique section	Sec. 6.2.34, Sec. 3.52,3.71 of the Guide

 

Comparison of solutions

Check	Strength of the section
Guide	100,35/100,69 = 0,997
SCAD	0,98
Deviation, %	1,7 %

 

Comments:

1. The strength check of oblique sections is performed by comparing a sum of lateral forces resisted by concrete and stirrups in the oblique section (Q_b + Q_sw), with a lateral force Q in the oblique section which is determined as a projection on the normal to the longitudinal axis of the element of the resultant of all external forces acting on the element on one side of the considered oblique section (Q = Q_max – q₁c). The lateral force in the normal section is taken as Q = 100,35 kN according to the Guide.
2. The data on the longitudinal reinforcement has to be specified in SCAD. Since it is not defined in the problem, the following reinforcement is used: class А240, rebars 2Ø6.