Structural System - Special Steel Moment Frame (SMF)
Frame type - Perimeter SMF
Number of stories - 9
Story heights - First story 18 ft; typical upper stories (2-9) 13 ft; total height 122 ft 
Analysis procedure - Equivalent Lateral Force (ELF); SDC D
Design standards - AISC 360, AISC 341, ASCE 7

## Material Properties
- Structural steel: **ASTM A992**
- Yield strength: **Fy = 50 ksi**
- Floor system: composite gravity beams on slab-on-metal-deck

## Gravity Loads
| Load Type | Magnitude |
|------------|-----------|
| Dead Load | 80 psf (composite floor: slab, deck, framing, superimposed) |
| Cladding Load | 25 psf (perimeter facade - precast/masonry) |
| Floor Live Load | 50 psf (office) + 15 psf partition allowance; reducible per Sec. 4.7 |
| Roof Live Load | 20 psf (Lr; reducible per Sec. 4.8) |

### Additional Notes
- Wind loads - V = 110 mph (ASCE 7-22), Exposure B; MWFRS per Ch. 26-27. Strength and drift expected to be seismic-governed; verify per direction.
- Member sizes for this archetype are typically drift-controlled rather than strength-controlled.

## Column Design Requirements
- Column sizes in lower stories never smaller than stories above 
- SMF columns selected to satisfy the strong-column/weak-beam ratio (AISC 341 E3.4a).

## Building Plan Geometry
  - Footprint: 150'-0" (Transverse/Y-axis) × 150'-0" (Longitudinal/X-axis).
  - Story Heights:
      - Level 1: 18'-0" (Floor-to-Floor)
      - Levels 2–9: 13'-0" (Floor-to-Floor, typical)
      - Total Height: 122'-0" (to roof parapet)
  - Column Grid Coordinates:
      - Transverse (Y-Axis): Grid Lines A to F (5 bays @ 30'-0" o.c.).
      - Longitudinal (X-Axis): Grid Lines 1 to 6 (5 bays @ 30'-0" o.c.).

LFRS System Classification
  - System Type: Special Moment Frames (SMF) conforming to AISC 341 and AISC 358
    (Seismic Design Category D/E).
  - Connection Profile: Prequalified Reduced Beam Section (RBS) moment
    connections.

To maximize interior space flexibility and torsional stiffness, the LFRS is
located entirely on the perimeter column lines:
Transverse Direction (Y-Axis LFRS):
  - Frame 1 (West Face): Located on Grid Line A, moment-connected between Grid
    Lines B and E (3 continuous bays, 90'-0" total width).
  - Frame 2 (East Face): Located on Grid Line F, moment-connected between Grid
    Lines B and E (3 continuous bays, 90'-0" total width).
Longitudinal Direction (X-Axis LFRS):
  - Frame 3 (South Face): Located on Grid Line 1, moment-connected between Grid
    Lines 2 and 5 (3 continuous bays, 90'-0" total width).
  - Frame 4 (North Face): Located on Grid Line 6, moment-connected between Grid
    Lines 2 and 5 (3 continuous bays, 90'-0" total width).

  - Stability Bracing of Beams (AISC 341 Section D1.2b): Both top and bottom
    flanges of SMF beams require lateral bracing. Maximum unbraced length must
    comply with highly ductile limits: L_b \le 0.086 \frac{r_y E}{F_y}

  * **SMF Beams:** W30 or W36
  * **SMF Columns:** W14

- Consider one size for all gravity beams outside the SMF frames and one size for all gravity columns outside the SMF frames - agent to determine.
- Consider rigid bases and rigid connections in the SMF frames.
- Consider pinned bases and pinned connections for gravity framing outside the SMF frames.

## Panel Zone Design in the SMF frames
- Joint panel zones designed per AISC 360, Equations J10-11 and J10-12.
- Doubler plates provided where required 
- Continuity plates: transverse stiffeners welded inside the column flanges, aligned with the beam flanges.

## Moment Connections
- All beam-to-column moment connections utilize **Reduced Beam Section (RBS)** connections per AISC 358.
