Seismic Base Shear Calculator
ASCE 7 ELF-style base shear prompts with ASCE/USGS hazard-source boundaries and engineering-review warnings
Free source-aware seismic base shear screen for structural review, early hazard conversations, and engineering study. Enter mapped spectral acceleration prompts (Ss, S1), site class, structural system, building weight, and period assumptions to review local SDC, Cs, and V rows. Outputs are planning prompts only; current ASCE 7 text, ASCE Hazard Tool or USGS output, site geotechnical data, adopted code, AHJ amendments, and licensed structural review control real design use.
Screen wind-load prompts on the same building
Wind Load Calculator →Review concrete-column source gaps for seismic load paths
Concrete Column Calculator →Screen footing bearing assumptions for review
Footing Bearing Pressure Calculator →Screen soil bearing assumptions before geotechnical review
Soil Bearing Capacity Calculator →How It Works
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Enter Hazard Prompts
Enter Ss, S1, TL, site class, and risk category from a current ASCE Hazard Tool or USGS design-map output and the project geotechnical/code basis. The app does not fetch or validate site coordinates, edition, or AHJ adoption.
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Select System Prompts
Choose a local structural-system row to expose R, Ω0, Cd, Ct, and x prompts. Verify actual system eligibility, height limits, detailing, and project framing with current ASCE 7 and qualified structural review.
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Enter Building Assumptions
Enter building height, seismic weight W in kips, and optional manual period. The app does not build seismic weight from project loads or apply every period cap, Cu limit, irregularity trigger, or modal-analysis requirement.
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Review Source Warnings
Review Fa, Fv, SDS, SD1, SDC, Cs prompt rows, and V = Cs × W together with the source warnings and unresolved gaps before carrying numbers into design software or stamped calculations.
Built For
- Structural teams screening ELF-style inputs before current ASCE and PE review
- Architects and owners comparing early source-boundary effects of system and site-class prompts
- Estimators collecting seismic questions for engineer-of-record review
- Engineering students studying base-shear arithmetic with source gaps visible
- Project teams checking whether hazard, geotechnical, and code inputs are missing
References
- ASCE/SEI 7-22 source pointer for governing seismic design context
- ASCE Hazard Tool source pointer for site-specific seismic parameters
- USGS Seismic Design Web Services source pointer for design-map parameters
- NIST unit-conversion source pointer for local unit prompts
Frequently Asked Questions
Learn More
Wind Load Design: ASCE 7-22 for Low-Rise Buildings
ASCE 7-22 wind load calculation step by step. Exposure categories, velocity pressure coefficients, MWFRS vs C&C pressures, roof uplift, and what changed from ASCE 7-10.
Seismic Base Shear: The ASCE 7-22 Equivalent Lateral Force Procedure
ASCE 7-22 ELF procedure from start to finish. Site coefficients, design spectral accelerations, seismic design category, R factor, period, and base shear calculation explained.
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