6.0 Overall Structural System Overview
The tower utilizes a hierarchical composite structural system integrating:
- Central reinforced core (primary spine)
- Radial floor truss network
- Outrigger + belt truss system
- Helical exterior mega-frame
- Dome crown structure
Primary Building Parameters
| Total Height | 900.0 m |
|---|---|
| Total Stories | 200 |
| Typical Floor Height | 4.5 m |
| Primary Material | Duplex Stainless Steel EN 1.4462 |
| Secondary Material | Stainless Steel 316L |
| Design Life | 150 years |
| Fire Resistance | Passive protection system |
6.1 Structural System — Exploded Hierarchy
Component Stack (Top → Foundation)
- Helical Dome Structure
- Outrigger Truss Levels (every 20 stories)
- Belt Truss Levels (every 10 stories)
- Radial Floor Trusses (every floor)
- Central Core (Duplex SS)
- Vertical Core Columns
- Core Perimeter Walls
- Diagonal Bracing (X‑brace system)
- Foundation Connection Ring Beam
- Foundation Pile System
6.2 Vertical Structural Zoning
Outrigger Levels
| Level 20 | 90.0 m |
|---|---|
| Level 40 | 180.0 m |
| Level 60 | 270.0 m |
| Level 80 | 360.0 m |
| Level 100 | 450.0 m |
| Level 120 | 540.0 m |
| Level 140 | 630.0 m |
| Level 160 | 720.0 m |
| Level 180 | 810.0 m |
| Level 200 | ~900.0 m |
Belt Truss Levels
- Every 10 stories
- Provide circumferential stiffness
Radial Floor Trusses
- Installed every floor
- Vertical spacing: 4.5 m
6.3 Typical Floor Structural Module
Geometry
| Module Diameter | 220.0 m |
|---|---|
| Central Core Diameter | Ø24.0 m |
| Floor Plate Type | Composite deck system |
Component Breakdown
1. Floor Deck
- Composite slab on steel deck
- Provides diaphragm action
2. Secondary Radial Members
| Material | Hollow Section (SS) |
|---|---|
| Diameter | Ø219 mm |
| Wall Thickness | 12.5 mm |
3. Primary Radial Trusses
| Diameter | Ø508 mm |
|---|---|
| Wall Thickness | 25 mm |
4. Perimeter Ring Beam
| Diameter | Ø2323 mm |
|---|---|
| Wall Thickness | 60 mm |
5. Perimeter Connections
Connects to helical mega‑frame nodes
6.4 Outrigger Truss System (Typical Level)
Configuration
- Truss Type: Vierendeel
- Depth: 8000 mm
- Material: Duplex Stainless Steel
Components
- Outrigger truss arms
- Ring beam interface
- Connection nodes
- Exterior mega‑frame linkage
- Central core anchoring
Engineering Logic
- Transfers overturning moment from core → perimeter
- Increases global stiffness
- Reduces lateral drift
6.5 Belt Truss System (Typical Level)
Components
- Belt truss mega ring (Ø2200 mm)
- Radial diagonal members
- Vertical stiffeners
- Frame connections
- Core interface
Function
- Ties perimeter columns together
- Distributes lateral loads evenly
- Enhances torsional resistance
6.6 Diagonal Bracing System (X‑Brace)
| Tube Diameter | Ø323 mm |
|---|---|
| Wall Thickness | 20 mm |
| Bracing Angle | 60° |
| Material | Duplex SS EN 1.4462 |
Components
- Diagonal tubes
- Node connectors
- Core column interface
- Floor-level tie-ins
Function
- Prevents buckling
- Provides shear resistance
- Stabilizes vertical columns
6.7 Structural Member Schedule
| Central Core Columns | Ø2400 mm — 80 mm — Duplex SS |
|---|---|
| Core Perimeter Walls | 1200 mm modules — 80 mm — Duplex SS |
| Primary Radial Truss | Ø508 mm — 25 mm — 24/floor |
| Secondary Radial Members | Ø219 mm — 12.5 mm — 48/floor |
| Perimeter Ring Beam | Ø2323 mm — 60 mm — 1/floor |
| Outrigger Truss | 8000 mm depth — 50 mm — 4/level |
| Outrigger Ring Beam | Ø2400 mm — 60 mm — 1/level |
| Belt Truss Mega Ring | Ø2200 mm — 50 mm — 1/level |
| Belt Truss Diagonals | Ø508 mm — 20 mm — 24/level |
| Diagonal Bracing | Ø323 mm — 20 mm — varies |
| Connection Nodes | Cast/Fabricated — varies |
6.8 Foundation Connection System
Ring Beam
- Diameter: Ø24.0 m
- Heavy structural ring
Pile System
- Pile Diameter: Ø1.5 m
- Number of Piles: 48
- Pile Spacing: 7.2 m
Components
- Base plate
- Anchor bolts (M64)
- Leveling nuts
- Welded connections
Function
- Transfers axial + lateral loads to ground
- Distributes load evenly across pile group
6.9 Foundation Layout Plan
- Circular pile arrangement
- Radial symmetry for uniform load transfer
- Core-aligned centroid
6.10 Helical Frame Connection Detail
Members
- Exterior mega-frame tubes: Ø508 mm
- Connection nodes: Cast steel
Connections
- Bolts: M64 (Grade 8.8 stainless steel)
- Welds: Full penetration groove welds
Function
- Transfers load between radial floors, helical frame, and ring beams
6.11 Design Load Summary
| Dead Load | 5.0 kN/m² |
|---|---|
| Live Load (Office) | 3.0 kN/m² |
| Wind Load | See Section 19 |
| Seismic Load | See Section 20 |
| Total Design Load | 8.0 kN/m² + environmental |
6.12 Material Properties — Duplex Stainless Steel EN 1.4462
| Yield Strength | 450 MPa |
|---|---|
| Tensile Strength | 650 MPa |
| Elastic Modulus | 200 GPa |
| Shear Modulus | 77 GPa |
| Density | 7850 kg/m³ |
| Poisson’s Ratio | 0.30 |
| Corrosion Resistance | Excellent |
| Fire Resistance | > 2.5 hours |
6.13 Engineering Logic
Global Structural Strategy
- Core = primary vertical load carrier
- Outriggers = moment transfer system
- Belt trusses = perimeter stiffening
- Helical frame = torsional + wind resistance
Load Path
- Floor loads → radial trusses
- Radial trusses → core + perimeter ring
- Lateral loads → outriggers
- Outriggers → exterior mega-frame
- Entire system → foundation ring → piles
Performance Behavior
- Wind: resisted via helical geometry + outriggers
- Seismic: distributed through ductile braced system
- Torsion: minimized via continuous ring structures
6.14 General Notes
- All welds: Full penetration groove welds unless noted
- All bolts: Stainless Steel M64 (Grade 8.8)
- Fabrication tolerance: ±5 mm
- Installation tolerance: ±10 mm
- All dimensions in millimeters unless stated
