ASCE 7-22 Loads and Design Skill

Purpose

This skill provides comprehensive access to ASCE 7-22 (Minimum Design Loads and Associated Criteria for Buildings and Other Structures), the authoritative US standard for determining structural loads.

Critical Distinction: ASCE 7 is a LOADS standard, not a material design standard. It tells you WHAT loads to apply, not HOW to design members.

When to Use This Skill

Trigger this skill when users ask about:

•Load combinations (LRFD, ASD)
•Wind loads, wind speed, exposure categories
•Seismic loads, base shear, response spectra
•Snow loads, ground snow, snow drift
•Load calculations per ASCE 7
•Risk Categories, Seismic Design Categories
•Environmental loads (tsunami, flood, ice, rain)

Do NOT use for:

•Steel member design → Use AISC 360
•Concrete member design → Use ACI 318
•Material properties, connection design

Document Structure

Available Chapters - Complete ASCE 7-22 Coverage

Chapter 1-5: General & Basic Loads

•
Chapter 1: General (31 KB)
- •Scope, definitions, risk categories, load factors
- •File: data/Chapter_01_General.md
•
Chapter 2: Combinations of Loads (16 KB)
- •LRFD and ASD combinations, seismic/flood/ice combinations
- •File: data/Chapter_02_Combinations_of_Loads.md
•
Chapter 3: Dead Loads, Soil Loads, and Hydrostatic Pressure (8 KB)
- •Dead load determination, soil lateral loads
- •File: data/Chapter_03_Dead_Loads_Soil_Loads_Hydrostatic_Pressure.md
•
Chapter 4: Live Loads (26 KB)
- •Floor live loads, roof live loads, reduction factors
- •File: data/Chapter_04_Live_Loads.md
•
Chapter 5: Flood Loads (10 KB)
- •Flood zones, flood loads, breakaway walls
- •File: data/Chapter_05_Flood_Loads.md

Chapter 6-10: Environmental Loads

•
Chapter 6: Tsunami Loads and Effects (98 KB)
- •Tsunami risk categories, inundation depths, design procedures
- •File: data/Chapter_06_Tsunami_Loads_and_Effects.md
•
Chapter 7: Snow Loads (24 KB)
- •Ground snow load, flat roof snow, snow drift, rain-on-snow
- •File: data/Chapter_07_Snow_Loads.md
•
Chapter 10: Ice Loads - Atmospheric Icing (12 KB)
- •Freezing rain, in-cloud icing, wind-on-ice
- •File: data/Chapter_10_Ice_Loads_Atmospheric_Icing.md

Chapter 11-23: Seismic Design

•
Chapter 11: Seismic Design Criteria (64 KB)
- •Site class, spectral response, SDC determination
- •File: data/Chapter_11_Seismic_Design_Criteria.md
•
Chapter 12: Seismic Design Requirements for Building Structures (177 KB)
- •ELF method, base shear, drift limits, irregularities
- •File: data/Chapter_12_Seismic_Design_Requirements_Building.md
•
Chapter 13: Seismic Design Requirements for Nonstructural Components (84 KB)
- •Architectural, mechanical, electrical components
- •File: data/Chapter_13_Seismic_Design_Requirements_Nonstructural.md
•
Chapter 14: Material-Specific Seismic Design and Detailing Requirements (11 KB)
- •Steel, concrete, masonry, wood seismic detailing
- •File: data/Chapter_14_Material_Specific_Seismic_Design.md
•
Chapter 15: Seismic Design Requirements for Nonbuilding Structures (43 KB)
- •Tanks, vessels, chimneys, towers, signs
- •File: data/Chapter_15_Seismic_Design_Requirements_Nonbuilding.md
•
Chapter 16: Nonlinear Response History Analysis (23 KB)
- •Ground motion selection, modeling, acceptance criteria
- •File: data/Chapter_16_Nonlinear_Response_History_Analysis.md
•
Chapter 17: Seismic Design Requirements for Seismically Isolated Structures (64 KB)
- •Base isolation systems, analysis procedures
- •File: data/Chapter_17_Seismic_Design_Seismically_Isolated.md
•
Chapter 18: Seismic Design Requirements for Structures with Damping Systems (81 KB)
- •Passive, active, and hybrid damping systems
- •File: data/Chapter_18_Seismic_Design_Structures_Damping_Systems.md
•
Chapter 19: Soil-Structure Interaction for Seismic Design (19 KB)
- •Foundation damping, kinematic interaction
- •File: data/Chapter_19_Soil_Structure_Interaction_Seismic.md
•
Chapter 20: Site Classification Procedure for Seismic Design (7 KB)
- •Site class A through F determination
- •File: data/Chapter_20_Site_Classification_Procedure_Seismic.md
•
Chapter 21: Site-Specific Ground Motion Procedures for Seismic Design (3 KB)
- •PSHA, DSHA procedures
- •File: data/Chapter_21_Site_Specific_Ground_Motion_Procedures.md
•
Chapter 22: Seismic Ground Motion and Long-Period Transition Maps (32 KB)
- •Spectral response maps, long-period maps
- •File: data/Chapter_22_Seismic_Ground_Motion_Maps.md
•
Chapter 23: Seismic Design Reference Documents (18 KB)
- •Referenced standards and documents
- •File: data/Chapter_23_Seismic_Design_Reference_Documents.md

Chapter 24-25: Reserved

•
Chapter 24: Reserved for Future Provisions
- •File: data/Chapter_24_Reserved_for_Future_Provisions.md
•
Chapter 25: Reserved for Future Provisions
- •File: data/Chapter_25_Reserved_for_Future_Provisions.md

Chapter 26-32: Wind & Tornado Loads

•
Chapter 26: Wind Loads - General Requirements (58 KB)
- •Wind speed, exposure, velocity pressure, gust factor
- •File: data/Chapter_26_Wind_Loads_General_Requirements.md
•
Chapter 27: Wind Loads on Buildings - MWFRS Directional Procedure (37 KB)
- •Main Wind Force Resisting System design
- •File: data/Chapter_27_Wind_Loads_MWFRS_Directional.md
•
Chapter 28: Wind Loads on Buildings - MWFRS Envelope Procedure (18 KB)
- •Simplified envelope procedure
- •File: data/Chapter_28_Wind_Loads_MWFRS_Envelope.md
•
Chapter 29: Wind Loads on Building Appurtenances and Other Structures (55 KB)
- •Rooftop equipment, tanks, signs, lattice structures
- •File: data/Chapter_29_Wind_Loads_Building_Appurtenances.md
•
Chapter 30: Wind Loads - Components and Cladding (114 KB)
- •Cladding pressures, roof systems, wall systems
- •File: data/Chapter_30_Wind_Loads_Components_and_Cladding.md
•
Chapter 31: Wind Tunnel Procedure (18 KB)
- •Wind tunnel testing requirements
- •File: data/Chapter_31_Wind_Tunnel_Procedure.md
•
Chapter 32: Tornado Loads (81 KB)
- •Tornado wind speeds, missile impact, design procedures
- •File: data/Chapter_32_Tornado_Loads.md

Total Coverage: 30 chapters, ~1.2 MB of content

Automation Scripts

Located in scripts/ directory:

•
smart_search.py - Category-aware chapter search
- •Maps keywords to relevant chapters
- •Usage: python3 smart_search.py "seismic base shear"
•
formula_finder.py - Extract formulas with context
- •Finds equations and shows variables
- •Usage: python3 formula_finder.py "V =" Chapter_12...md
•
load_combinator.py - Generate applicable load combinations
- •LRFD and ASD combinations
- •Usage: python3 load_combinator.py --design LRFD --loads D,L,W,S

Reference Files

Located in references/ directory (to be created):

•chapter-structure.md - Navigation guide
•load-combinations-index.md - Quick reference for Ch 2
•formulas-index.md - 50+ key formulas
•glossary.md - Technical terms
•symbols.md - Mathematical notation
•workflows.md - Design workflows
•risk-categories-guide.md - Risk Category I-IV
•seismic-categories-guide.md - SDC A-F
•wind-exposure-guide.md - Exposure B/C/D

Workflow Types

1. Formula Query Workflow

Trigger: User asks for a specific formula or equation

Process:

•Identify the load type (wind, seismic, snow, etc.)
•Use smart_search.py to find relevant chapter
•Use formula_finder.py to extract formula with context
•
Present formula with:
- •Equation number (e.g., "Eq. 12.8-1")
- •Variable definitions
- •Context (when to use, limitations)
- •Units

Example:

code

User: "Show me the seismic base shear formula"

Response:
The seismic base shear is calculated using Equation 12.8-1:

V = CsW

Where:
- V = Seismic base shear
- Cs = Seismic response coefficient (Eq. 12.8-2 through 12.8-6)
- W = Effective seismic weight

From Chapter 12, Section 12.8: Equivalent Lateral Force Analysis

The seismic response coefficient Cs is determined by:
Cs = SDS / (R/Ie)  [Eq. 12.8-2]

Subject to:
- Cs need not exceed: Cs = SD1 / [T(R/Ie)]  [Eq. 12.8-3]
- Cs shall not be less than: Cs = 0.044SDSIe ≥ 0.01  [Eq. 12.8-5]

Reference: ASCE 7-22 Chapter 12.8

2. Load Combination Query Workflow

Trigger: User asks about load combinations, LRFD, ASD

Process:

•Determine design method (LRFD or ASD)
•Identify all applicable loads
•Use load_combinator.py to generate combinations
•Explain when each combination controls
•Note any special requirements (flood, seismic, ice)

Example:

code

User: "What LRFD load combinations do I need for Dead, Live, Wind, and Snow?"

Response:
For LRFD with D, L, W, and S loads, use these combinations per ASCE 7-22 Chapter 2:

1. 1.4D                                  (Eq. 2.3-1)
2. 1.2D + 1.6L + 0.5(Lr or S or R)     (Eq. 2.3-2)
3. 1.2D + 1.6(Lr or S or R) + (L or 0.5W)  (Eq. 2.3-3)
4. 1.2D + 1.0W + L + 0.5(Lr or S or R)  (Eq. 2.3-4)

Note:
- Combination 1 typically controls for compression members
- Combination 2 usually controls for live-load-dominated structures
- Combination 4 typically controls when wind is significant
- For each combination, check both +W and -W directions

[Runs load_combinator.py to generate full list]

3. Calculation Query Workflow

Trigger: User wants to calculate a specific load value

Process:

•Identify calculation type (wind pressure, base shear, snow load, etc.)
•Gather required inputs from user
•Reference appropriate chapter sections
•Show step-by-step calculation with equation numbers
•Provide final result with units

Example:

code

User: "Calculate wind pressure for 120 mph, Exposure C, at 30 ft height"

Response:
Wind pressure calculation per ASCE 7-22 Chapter 26:

Step 1: Velocity Pressure (Eq. 26.10-1)
qz = 0.00256 Kz Kzt Kd Ke V²

Given:
- V = 120 mph (basic wind speed)
- Exposure C
- z = 30 ft

Assuming:
- Kz = 0.85 (Exposure C at 30 ft, from Table 26.10-1)
- Kzt = 1.0 (no topographic effects)
- Kd = 0.85 (assuming Risk Category II, Table 26.6-1)
- Ke = 1.0 (sea level)

qz = 0.00256 × 0.85 × 1.0 × 0.85 × (120)²
qz = 28.3 psf

Reference: ASCE 7-22 Section 26.10

4. Terminology Query Workflow

Trigger: User asks "what is..." or definition questions

Process:

•Search glossary.md for term
•If not in glossary, search chapter text
•Provide definition with context
•Link to relevant chapter section
•Give practical example if helpful

Example:

code

User: "What is Seismic Design Category?"

Response:
Seismic Design Category (SDC) is a classification from A through F that determines the level of seismic design requirements for a structure.

Per ASCE 7-22 Chapter 11.6:
- SDC A: Minimal seismic risk
- SDC B-C: Moderate seismic risk
- SDC D-F: High seismic risk (most stringent requirements)

SDC is determined by:
1. Risk Category (Table 1.5-1)
2. Site Class (Chapter 20)
3. Spectral Response Parameters (SDS, SD1)
4. Using Tables 11.6-1 and 11.6-2

Higher SDC requires:
- More rigorous structural system requirements
- Greater detailing requirements
- Additional analysis procedures
- Special inspection

Reference: ASCE 7-22 Section 11.6

5. Symbol Query Workflow

Trigger: User asks about a variable or symbol

Process:

•Check symbols.md reference file
•Search relevant chapter for symbol definition
•
Provide:
- •Symbol meaning
- •Units
- •Typical range of values
- •Where it's used

Example:

code

User: "What does SDS mean in seismic design?"

Response:
SDS = Design spectral response acceleration parameter at short periods

Per ASCE 7-22 Section 11.4.5:
- Units: Dimensionless (fraction of g)
- Calculated as: SDS = (2/3) Sms
- Where Sms = MCER spectral response acceleration (short period)

SDS is used to:
1. Determine Seismic Design Category (Table 11.6-1)
2. Calculate seismic response coefficient Cs (Eq. 12.8-2)
3. Determine structural system limitations

Typical values:
- Low seismicity: SDS < 0.167g
- Moderate: 0.167g ≤ SDS < 0.50g
- High: SDS ≥ 0.50g

Reference: ASCE 7-22 Sections 11.4.5, 11.6

6. Risk/Design Category Query Workflow

Trigger: Questions about building classification, risk category, SDC

Process:

•
For Risk Category:
- •Reference Table 1.5-1
- •Ask about building occupancy/function
- •Determine Category I, II, III, or IV
•
For Seismic Design Category:
- •Need: Risk Category, SDS, SD1, Site Class
- •Use Tables 11.6-1 and 11.6-2
- •Determine SDC A through F

Example:

code

User: "How do I determine the Risk Category for an office building?"

Response:
Risk Category determination per ASCE 7-22 Table 1.5-1:

Standard Office Building:
- Occupancy: Business (office)
- Risk Category: II (default for most buildings)

Risk Categories explained:
- **Category I**: Low hazard (agricultural, minor storage)
- **Category II**: Standard occupancy (offices, residential, retail) ← Most common
- **Category III**: Substantial hazard (schools, jails, large assembly)
- **Category IV**: Essential facilities (hospitals, fire stations, emergency shelters)

Impact of Risk Category:
- Importance factors (Ie for seismic, Is for snow)
- Load duration and return periods
- Seismic Design Category determination

For your office building, use Risk Category II unless it:
- Houses >5,000 people
- Contains hazardous materials
- Is designated as essential facility

Reference: ASCE 7-22 Table 1.5-1

7. Comparison Query Workflow

Trigger: "What's the difference between..." or comparison questions

Process:

•Identify the two concepts being compared
•Create side-by-side comparison table
•Explain when to use each
•Provide examples

Example:

code

User: "What's the difference between LRFD and ASD load combinations?"

Response:
LRFD vs ASD Load Combinations (ASCE 7-22 Chapter 2):

| Aspect | LRFD (Section 2.3) | ASD (Section 2.4) |
|--------|-------------------|-------------------|
| **Full Name** | Load and Resistance Factor Design | Allowable Stress Design |
| **Also Called** | Strength Design | Working Stress Design |
| **Load Factors** | Higher (1.2D, 1.6L, etc.) | Lower (1.0D, 1.0L, etc.) |
| **Philosophy** | Factor loads up, factor resistance down | Unfactored loads, reduced allowable stress |
| **Basic Combo** | 1.2D + 1.6L | D + L |
| **Wind Combo** | 1.2D + 1.0W + L + 0.5(Lr or S) | D + 0.75L + 0.75(0.6W) + 0.75(Lr or S) |

**When to use:**
- LRFD: Modern codes, steel (AISC 360), concrete (ACI 318)
- ASD: Older codes, wood (NDS), masonry, aluminum

**Key Difference:**
LRFD combinations produce higher loads (factored up), intended for use with factored resistance equations.
ASD combinations use service loads, intended for use with allowable stress values.

You CANNOT mix them - use LRFD loads with LRFD resistance, ASD loads with ASD resistance.

Reference: ASCE 7-22 Sections 2.3 and 2.4

8. Procedure Query Workflow

Trigger: "How do I...", step-by-step questions

Process:

•Identify the design procedure requested
•Outline step-by-step process
•Reference relevant sections
•Provide decision points and checks
•List required inputs

Example:

code

User: "How do I perform equivalent lateral force seismic analysis?"

Response:
Equivalent Lateral Force (ELF) Procedure per ASCE 7-22 Chapter 12.8:

**Step 1: Verify ELF Method is Applicable (Section 12.6)**
- Check building height limits (Table 12.6-1)
- Check for structural irregularities (Tables 12.3-1, 12.3-2)
- Some systems/heights require modal analysis instead

**Step 2: Determine Seismic Parameters (Chapter 11)**
- Risk Category (Table 1.5-1)
- Site Class (Chapter 20)
- Spectral values SDS and SD1 (Section 11.4)
- Seismic Design Category (Section 11.6)

**Step 3: Calculate Seismic Response Coefficient Cs (Section 12.8.1.1)**
Cs = SDS / (R/Ie)  [Eq. 12.8-2]

Subject to limits:
- Maximum: Cs = SD1 / [T(R/Ie)]  [Eq. 12.8-3]
- Minimum: Cs = 0.044SDSIe ≥ 0.01  [Eq. 12.8-5]

**Step 4: Determine Approximate Period Ta (Section 12.8.2.1)**
Ta = Ct × hn^x  [Eq. 12.8-7]

Where Ct and x are from Table 12.8-2

**Step 5: Calculate Seismic Base Shear V (Section 12.8.1)**
V = CsW  [Eq. 12.8-1]

Where W = effective seismic weight

**Step 6: Distribute Vertical Forces (Section 12.8.3)**
Fx = CvxV  [Eq. 12.8-11]

Where Cvx from Eq. 12.8-12

**Step 7: Check Story Drift (Section 12.12.1)**
Δ < Δa (allowable story drift from Table 12.12-1)

**Required Inputs:**
- Building geometry (height, floor areas)
- Dead loads (seismic weight W)
- Structural system (determines R, Ω0, Cd)
- Site seismic parameters (SDS, SD1)

Reference: ASCE 7-22 Chapter 12.8

Quick Reference Tables

Load Symbols (Chapter 2.2)

Symbol	Meaning	Reference
D	Dead load	Section 3.1
L	Live load (floor)	Section 4.7
Lr	Roof live load	Section 4.9
S	Snow load	Chapter 7
R	Rain load	Section 8.3
W	Wind load	Chapter 26-30
E	Seismic load	Section 12.4
H	Lateral earth pressure	Section 3.2
Fa	Flood load	Chapter 5
Wi	Wind-on-ice	Section 10.4

Risk Categories

Category	Description	Examples
I	Low hazard	Agricultural, minor storage
II	Standard	Offices, residential, retail
III	Substantial	Schools, jails, large assembly (>300)
IV	Essential	Hospitals, fire stations, emergency

Seismic Design Categories

SDC	Seismic Risk	Typical SDS Range
A	Minimal	SDS < 0.167
B	Low	0.167 ≤ SDS < 0.33
C	Moderate	0.33 ≤ SDS < 0.50
D	High	SDS ≥ 0.50
E	Very High	(Special conditions)
F	Extreme	(Near major faults)

Wind Exposure Categories

Exposure	Terrain Description	Surface Roughness
B	Urban/suburban, many obstructions	High
C	Open terrain, scattered obstructions	Medium
D	Flat, unobstructed (water, desert)	Low

Performance Optimization

Context Management

Priority Loading Order:

•Load Chapter 2 (combinations) - always needed (16 KB)
•Load specific load chapter based on query type
•Load calculation scripts - only when computing

File Sizes by Category:

Small Files (< 20 KB): Quick to load

•Chapter 1: 31 KB, Chapter 2: 16 KB, Chapter 3: 8 KB
•Chapter 5: 10 KB, Chapter 10: 12 KB, Chapter 14: 11 KB
•Chapter 20: 7 KB, Chapter 21: 3 KB, Chapter 28: 18 KB, Chapter 31: 18 KB

Medium Files (20-60 KB): Load as needed

•Chapter 4: 26 KB, Chapter 7: 24 KB, Chapter 16: 23 KB
•Chapter 19: 19 KB, Chapter 22: 32 KB, Chapter 23: 18 KB
•Chapter 15: 43 KB, Chapter 26: 58 KB, Chapter 27: 37 KB
•Chapter 29: 55 KB

Large Files (60-120 KB): Load selectively

•Chapter 6: 98 KB, Chapter 11: 64 KB, Chapter 17: 64 KB
•Chapter 18: 81 KB, Chapter 13: 84 KB, Chapter 30: 114 KB
•Chapter 32: 81 KB

Very Large File:

•
Chapter 12: 177 KB (seismic design - load only relevant sections)
- •Use formula_finder.py to extract specific sections
- •Search for section numbers (e.g., "12.8" for ELF method)
- •Don't load entire file unless necessary

Search Strategy

Use smart_search.py first:

python

python3 smart_search.py "user query"

This maps keywords to chapters before loading files.

For formulas, use formula_finder.py:

python

python3 formula_finder.py "pattern" chapter_file.md

Extracts equations without loading full file into context.

Response Quality Checklist

When responding to ASCE 7 queries, ensure:

✅ Cite Equation Numbers: Always include equation numbers (e.g., "Eq. 12.8-1") ✅ Cite Section Numbers: Reference specific sections (e.g., "Section 12.8.3") ✅ Include Units: Always specify units (psf, mph, g, kips, etc.) ✅ Clarify Scope: Remind users ASCE 7 is for loads, not member design ✅ Check Applicability: Verify method applies to user's situation ✅ Provide Context: Explain when/why to use specific provisions ✅ List Assumptions: State any assumptions made in calculations ✅ Link Chapters: Cross-reference related chapters (e.g., Ch 11 → Ch 12)

ASCE 7 Special Considerations

1. Loads vs. Design Distinction

CRITICAL: Always clarify to users:

"ASCE 7 determines LOADS (forces) to apply to structures. It does NOT design members.

For member design, use:

•Steel: AISC 360
•Concrete: ACI 318
•Wood: NDS
•Masonry: TMS 402"

2. Load Combination Selection

Users often confused about which combinations apply. Always:

•Ask about ALL loads present (D, L, Lr, S, R, W, E, H, etc.)
•Ask design method (LRFD or ASD)
•Check for special loads (flood, ice, seismic detailed)
•Use load_combinator.py to generate full list

3. Seismic Design Flow

Seismic design has dependencies:

code

Risk Category (Ch 1) →
Site Class (Ch 20) →
Spectral Values (Ch 11) →
SDC (Ch 11) →
Structural System Selection (Ch 12) →
Analysis Method (Ch 12) →
Design Forces (Ch 12) →
Member Design (AISC/ACI/etc.)

Always guide users through this flow.

4. Wind Load Complexity

Wind loads have multiple procedures:

•Method 1: Simplified (limited applicability)
•Method 2: Analytical (most common)
•Method 3: Wind tunnel
•Method 4: Directional with regional data

Ask about building characteristics to determine applicable method.

Error Handling

Missing Information

If user query lacks required information:

code

"To determine [X], I need:
- Building height
- Risk Category
- [Other required inputs]

Please provide these details."

Out of Scope

If query is about member design, not loads:

code

"ASCE 7 provides the loads, but member design is covered by:
- Steel: AISC 360
- Concrete: ACI 318

Would you like help determining the loads per ASCE 7, or do you need assistance with member design?"

Ambiguous Query

If unclear what user wants:

code

"I can help with several aspects of [topic]:
1. Load calculation procedure
2. Load combinations
3. Formula lookup
4. Definition/terminology

Which would be most helpful?"

Common User Mistakes to Correct

•Mixing LRFD and ASD: Gently correct and explain difference
•Confusing loads with design: Clarify ASCE 7 scope
•Wrong Risk Category: Help determine correct category
•Incomplete load combinations: Ensure all applicable loads included
•Wrong exposure category: Ask about surrounding terrain
•Ignoring special loads: Check for flood zones, high seismic, etc.

Integration with Other Tools

Python Scripts Usage

From skill responses:

code

[Runs smart_search.py with query: "wind load"]
[Runs formula_finder.py on Chapter_26_Wind_Loads_General_Requirements.md]
[Runs load_combinator.py with --design LRFD --loads D,L,W]

File Reading Strategy

Efficient approach:

•Use smart_search first (small script)
•Load only relevant chapter (not all 6 chapters)
•Search within chapter for specific section
•Extract only needed portion (use formula_finder if possible)

Last Updated: 2025-11-20 ASCE 7 Edition: 2022 Status: Production Ready - Complete Coverage (30/32 chapters) Note: Chapters 8 (Rain Loads) and 9 (Reserved) not available due to source data limitations