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eng.seismic-base-shear Calculator
Calculates seismic base shear from the equivalent lateral force procedure per ASCE 7 from spectral acceleration, weight, and period. The seismic force coefficient Cs = SDS/(R/Ie) — response modification coefficient R accounts for ductility (8 for special moment frames, 3 for ordinary frames).
Inputs
W Kn
Body or object weight. For health calculators, usually in kg or lbs.
Sa G
Rate of velocity change (m/s²). Earth's gravity: 9.81 m/s². Objects in free fall accelerate at this rate.
R Factor
A multiplier applied in the calculation.
Ie
A multiplier applied in the calculation.
Cd
A multiplier applied in the calculation.
Results
seismic base shear V (kN)
Sample size or count used in the calculation.
seismic coefficient Cs
Sample size or count used in the calculation.
V/W ratio
The proportional relationship between two quantities.
Cs = Sa·Ie/R
Reference formula or conversion factor shown for context.
drift amplification
The value at the specified point or condition.
R factor examples
A dimensionless multiplier applied in the calculation.