Seismic Analysis

Modeling and calculating a structure's forces, deformations, accelerations, and damage-sensitive demands under earthquake ground motion using a code-appropriate static or dynamic procedure.

Version

v2 · 2026-09-06 · History

Domain-specific #

2743

Origin domain

engineering

Subdomain

earthquake engineering

Aliases

Structural seismic analysis, Earthquake response analysis

Core Idea

Seismic analysis models and calculates how a building or nonbuilding structure responds to earthquake ground motion. It transforms a site hazard representation and a structural model into demands such as base shear, member forces, story drift, acceleration, deformation, instability, and damage-sensitive response for design or assessment.

The method must match the objective and structural regime. Options include equivalent lateral force, modal response-spectrum, linear response-history, nonlinear static pushover, and nonlinear response-history analysis. Greater model fidelity does not automatically mean greater decision accuracy: ground-motion selection, damping, component behavior, soil–structure interaction, and acceptance criteria remain consequential.

Scope of Application

The abstraction supports new design, existing-building evaluation, retrofit, performance-based engineering, equipment qualification, bridges, dams, industrial facilities, and isolated or damped structures. ASCE/SEI 7 selects and constrains procedures based on structural characteristics and risk; FEMA/NIST guidance explains modeling and application.

Irregular, tall, essential, or highly nonlinear systems may require response-history or other advanced methods. Project-specific laws, codes, peer review, and professional judgment govern actual use.

Clarity

State the governing standard and edition, hazard level, performance objective, site class, structural model, damping, analysis method, ground-motion selection/scaling, nonlinear properties, response combinations, and acceptance criteria. Separate expected response from code-design response after modification factors.

Manages Complexity

Seismic analysis compresses interacting inertia, stiffness, damping, mode shape, yielding, and ground motion into traceable demand calculations. Its hierarchy of procedures lets simpler models serve regular low-complexity structures while escalating representation when higher modes, torsion, and inelastic response materially affect the decision.

Abstract Reasoning

1. Define the decision, performance objective, and governing standard.
2. Characterize site hazard and input motion.
3. Build and validate mass, stiffness, damping, strength, and boundary models.
4. Determine whether static, spectral, or history analysis is admissible.
5. Calculate modes and participation where required.
6. Apply input, combinations, scaling, and nonlinear rules.
7. Extract forces, drifts, accelerations, deformations, and instabilities.
8. Test sensitivity to records and uncertain parameters.
9. Compare demand with code or performance capacity.
10. Iterate design and document assumptions.

Knowledge Transfer

The portable pattern is select a model-fidelity tier for a forced dynamic system according to decision consequence and nonlinear response. It transfers to wind, blast, vibration, impact, and machinery analysis. The proposed immediate parent is Perturbation.

Relationships to Other Abstractions

Current abstraction Seismic Analysis Domain-specific

Parents (1) — more general patterns this builds on

• Seismic Analysis is a kind of Perturbation Prime

  Perturbation is the proposed immediate parent.

Hierarchy paths (2) — routes to 2 parentless roots

• Seismic Analysis → Perturbation → Observability

Show alternative path (1)

Neighborhood in Abstraction Space

Seismic Analysis sits in a sparse region of the domain-specific corpus (95^th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Unclustered & Miscellaneous (1565 abstractions)

Nearest neighbors

• Long-period ground motion — 0.79
• Duhamel's Integral — 0.77
• Arias intensity — 0.77
• Operational modal analysis — 0.76
• Self-buckling — 0.76

Computed from structural-signature embeddings · 2026-09-08