D1.B.3.2 Design steps for Steel Beam with Web Opening
At the location of web holes, the capacity of the section is determined using the rules explained below.
![](GUID-D11E91EA-5346-4E7F-B8BB-E00384475DA4-low.png)
Opening configurations for steel beams with unreinforced opening
![](GUID-67737284-EBBA-4603-9B5E-F82F137F38B3-low.png)
Opening configurations for steel beams with reinforced opening
Section Properties Required:
- As = Cross-sectional area of steel in the unperforated member (at a section along the beam where there is no opening)
- d = Depth of beam
- tw = Thickness of web
- bf = Width of flange
- tf = Thickness of flange
- Z = Plastic section modulus of member without opening
- J = Torsional constant of the beam
- L = Length of the member
- Lb = Unbraced length of compression flange
Opening Information Required:
- e = Eccentricity of opening, specified using the HECC parameter (distanced from mid-depth of beam to mid-depth of the opening) = | e |
- sign convention for eccentricity: upward eccentricity + e, downward eccentricity - e
Loading:
- Vu = Factored shear at different opening locations
- Mu = Factored bending moment at different opening locations
Calculated Parameters
Circular Opening Properties:
Unreinforced Opening Properties:
- ho = Do for bending
- ho = 0.9 Do for shear
- ao = 0.45 Do
Reinforced Opening Properties:
- ho = Do for bending and shear
- ao = 0.45 Do
Tee Properties:
Refer to Figure 2.17(a), above
- st = Depth of top tee = d/2 – (ho / 2 + e)
- sb = Depth of bottom tee = d/2 – (ho / 2 - e)
Reinforcement Properties:
- Ar = Area of reinforcement on each side of the opening
- tr = Thickness of reinforcement bar
- br = Width of reinforcement bar
- Dr = Depth of reinforcement bar