👉Design Requirements of Shear Walls according to EBCS (Ethiopian Building Code Standards)

🚧1. Purpose of Shear Wall

💫Shear walls are structural elements provided to:
⏺Resist lateral loads (earthquake & wind)
⏺Control story drift
Increase stiffness and strength of buildings
⏺Improve seismic performance, especially for mid- and high-rise buildings

🚧2. Location & Layout Requirements

💫According to EBCS-8: Shear walls shall be:
⏺Continuous from foundation to roof
⏺Uniformly distributed in plan to avoid torsion
⏺Preferably placed:
At building cores (stairs, elevators)
⏺Symmetrically in both X and Y directions
⏺Avoid: Sudden termination of walls and Large offsets or irregular wall alignment

🚧3. Thickness Requirements
As per EBCS-2:

💫Minimum wall thickness:
⏺150 mm for low-rise buildings
⏺200 mm or more for multi-storey buildings

⚡️Thickness must satisfy:Slenderness limits,Fire resistance,Durability requirements

🚧4. Material Requirements
Concrete

⏺Minimum concrete grade:
C25 (fck ≥ 25 MPa) for seismic areas
⏺Good compaction and curing are mandatory

⚡️Reinforcement Steel
⏺Deformed bars with:
fy = 300–500 Mpa

🚧5. Reinforcement Requirements (Very Important)

🏷5.1 Vertical Reinforcement
Minimum vertical steel ratio:
ρv ≥ 0.0025 (0.25%)
Bars: Uniformly distributed
⏺Minimum bar diameter: Ø10 mm
⏺Spacing: ≤ 300 mm

🏷5.2 Horizontal Reinforcement
⏺Minimum horizontal steel ratio: ρh ≥ 0.0025
⏺Spacing: ≤ 300 mm

📍Purpose:
⏺Control cracking
⏺Improve ductility

🚧6. Boundary Elements (Seismic Requirement)

⏺According to EBCS-8: Boundary elements are mandatory when:

🔰Wall is heavily stressed High axial force exists
🎲Requirements:

⏺Confined reinforcement (ties/stirrups)
⏺Tie spacing: ≤ 100 mm near ends
⏺Boundary zone width: ≥ max( wall thickness, 300 mm )

🚧7. Openings in Shear Walls

💫Openings (doors/windows) must:
⏺Be limited in size
⏺Be properly reinforced around edges
⏺Lintels and coupling beams:
Must be designed for shear + bending
⏺Require diagonal reinforcement in seismic zones

🚧8. Seismic Design Provisions (EBCS-8)

💫Shear walls must be designed for:
⏺Design base shear
⏺Overstrength factor
⏺Ductile detailing is compulsory:
⏺Proper anchorage
⏺Lap splices away from critical zones
⏺Drift limits must be checked:
Inter-story drift ≤ allowable limit

🚧9. Foundation Connection

💫Shear walls must be:

⏺Rigidly connected to foundation
⏺Proper dowel bars and development length provided
⚡️Foundation must resist:
⏺Overturning
⏺Sliding

🚧10. Construction & Quality Control

💫Accurate bar placement
Proper cover:

⏺≥ 25–40 mm depending on exposure
⏺Continuous supervision is required

📜Conclusion

💫According to EBCS, a shear wall must be:

⏺Properly located
⏺Adequately thick
⏺Correctly reinforced
⏺Detailed for ductility and seismic resistance
⏺Fully integrated with foundation and slabs

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