Albarakah 165 ft Marquee

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50.16m Ø Circular Structure • Ring-1 (2.15 Ton) + 5-Part Rafters

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Rafter Colors Pedestal Heatmap Deviation Vectors

Layers

RAFTER BAY 1 PEB Member

Main Radial Rafter Truss

Built-up tapered I-section with dual moment haunches.

Material Profile: ASTM A36

PEB Design Note:

Ring-1: 5.58m Ø Master Compression Crown

Weight: 2,153.90 kg

Complete Fabrication Detailing from Tekla Structures (Shop Drawing pp. 1-2)

Outer Diameter

5,580 mm

Outer Radius $R=2,790 ext{mm}$ ($18.3 ext{ft}$)

Inner Throat Diameter

4,780 mm

Throat Radius $R=2,390 ext{mm}$ ($400 ext{mm}$ Box)

Total Assembly Weight

2,153.90 kg

Single Shop-Welded Crown Assembly

Thrust Equilibrium

Σ Fr = 0

Hoop Compression: $T = H / (2\sin 9^\circ)$

Tekla Structures Shop Drawing Sheet CIRCULAR MARQUEE FABRICATION.pdf — Page 1 (Ring-1 Assembly)

Click image to open full ultra-high-resolution drawing in new window.

Detailed Parts Schedule for Ring-1 (DWG pp. 1-2)

Mark	Profile Size	Qty	Cut Length	Total Wt (kg)	Role in PEB Crown Hub
Ring-1 & of-39	D2790 / PL 200x12	2	Circular Ring ($R_{in}=2390, R_{out}=2790$)	306.38	Continuous circular top & bottom annular ring plates
sp-2	PL 12x200	20	470 mm	177.10	Projecting Rafter Connection Shoes (6xM20 bolt holes)
clp-1	FL 6x140	62	149 mm	61.32	Cleat clips with 4x14mmØ holes for purlins ($162^\circ$ chord)
web-5 to 35	PL 5x300	20	730 mm to 2,348 mm	365.10	20 Radial Outrigger Arms with 45mm/300mm roof slope bevel
web-36	PL 5x300	6	1,284 mm	90.76	Internal box diaphragms
web-38	PL 8x350	1	7,098 mm	155.86	Continuous heavy circumferential perimeter web plate
web-39	PL 8x320	1	1,101 mm	22.12	High-shear throat transition diaphragm
if-5 to 39	FL 8x191	25	684 mm to 2,574 mm	489.84	Inner throat flange segments ($R=2,390 ext{mm}$)
of-3 to 38	FL 8x191	24	730 mm to 2,574 mm	515.43	Outer perimeter flange segments ($R=2,790 ext{mm}$)
Total Shop Assembly Weight:				2,153.90 kg	~2.15 Metric Tons (Monolithic Crown)

Full Rafter Schedule: RAF-1 Through RAF-5

22.77m Prefab + Stubs

Segmented Pre-Engineered Tapered Rafter Design (20 Radial Bays, Dual Moment Haunches)

Dual Moment Haunch Longitudinal Profile

 EAVE KNEE HAUNCH                          MID-SPAN BELLY HAUNCH                         CROWN SHOE
 (4,000 mm Length)                           (4,368 mm Length)                            (Ring-1)
 ┌───────────────┐                           ┌───────────────┐                           ┌───────┐
 │               ▼                           ▼               ▼                           ▼       │
 █▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀█───────┤
 █ 600mm                                  550mm                                  300mm   │Ring-1 │
 █ ──┐                                  ┌───┴───┐                                        │5.58m Ø│
 █   └─── 300mm ────────────────────────┘       └───────────────────────── 300mm ────────█───────┤
 █                                                                                       └───────┘
 └── RAF-1 (6,133mm) ──┴── RAF-2 (6,134mm) ──┴── RAF-3 (2,184mm) ──┴── RAF-4 (2,184mm) ──┴── RAF-5 (6,134mm) ──┴─ Stub ─┘

5-Segment Prefabrication Bill of Materials

Mark	Slope Length	Web Depth & Plate	Flanges	Structural Haunch Function	Qty (20 Bays)
RAF-1	6,133 mm	Tapers 600mm -> 300mm (PL 5)	FL 8x191	Column Knee Haunch (4,000mm moment zone)	20 Nos.
RAF-2	6,134 mm	Straight 300mm (PL 5x300)	FL 8x191	Intermediate lower roof span	20 Nos.
RAF-3	2,184 mm	Deepens 300mm -> 550mm (PL 5)	FL 8x191	Mid-Span Belly Haunch Drop (at 15,244mm)	20 Nos.
RAF-4	2,184 mm	Tapers 550mm -> 300mm (PL 5)	FL 8x191	Mid-Span Belly Recovery (4,368mm belly)	20 Nos.
RAF-5	6,134 mm	Straight 300mm (PL 5x300)	FL 8x191	Upper roof span to Crown Ring-1	20 Nos.
Apex Stub	174mm ~ 2,129mm	Transition shoe plate (PL 12x200)	FL 8x191	Absorbs 1,601mm site survey error	20 Nos.

Full 20-Column Concrete & Steel Audit

Surveyed As-Built Geometry vs Design Clear Heights vs Fabricated Columns

Critical Clash Audit: Pedestals are cast with severe radial eccentricity ($1,601 ext{ mm}$ maximum deviation) and uneven levels up to $+65 ext{ mm}$ above FFL. While G.A. drawings specified custom clear heights ($5209$ to $5449 ext{ mm}$) to adapt, the shop drawings detailed all 9 pieces of COL-10 to a single uniform length of 5,384 mm, guaranteeing major erection failure if not re-detailed.

#	Grid / Location	Tag	Surveyed Radius	Radial Dev (ΔR)	TOC Offset	GA Clear Ht	Fab Length	Height Clash	Status	Action

Final Engineering Safety Verdict

⛔ NOT SAFE TO EXECUTE AS-IS

Senior PEB Structural Designer Forensic Review

MANDATORY HOLD ORDER: DO NOT PROCEED WITH ERECTION

Proceeding with erection right now will lead to severe on-site clashing, forced geometric warping, locked-in residual assembly stresses, and potential structural distress/instability under wind and live loads.

The Fatal COL-10 Fabrication Clash

G.A. drawings specified 9 custom heights ($5209$ to $5449 ext{mm}$), but the fabrication drawing detailed all 9 pieces of COL-10 to an identical 5,384 mm length. On Grid 3 the column will be 65mm too short, and on Grid 4 it will clash by 175mm too long!

Disrupted Ring-1 Equilibrium

The 5.58m central ring relies strictly on 20-fold radial symmetry ($\sum F_r = 0$) to convert inward rafter thrust into pure hoop compression. Because concrete radii vary by 1,601 mm ($5.25 ext{ ft}$), unbalanced thrust will induce severe in-plane ovalization and out-of-plane torsional buckling.

Concrete Pedestal Level Errors (+65 mm)

A 65 mm vertical step across pedestals causes severe roof slope warping, rainwater ponding along eaves gutters, fabric membrane wrinkling, and eccentric prying on the 24mm anchor bolts.

Purlin & Strut Chord Mismatches

Purlins (`P-1` to `P-23`) were cut to nominal lengths. On the eccentric 1.6m out-of-round oval, chord distances between rafters misalign, causing bolt holes to miss cleats (`clp-1`).

3-Step Mandatory Protocol to Make Execution 100% Safe:

Civil Rectification: Level all 20 concrete pedestals to a uniform Finished Floor Level ($ ext{F.F.L} + 0.00$) within $\pm 3 ext{mm}$ tolerance by chiseling high pedestals or grouting low pedestals.
Column Height Re-Detailing: Re-cut or re-fabricate the 9 `COL-10` pieces to individually match the actual surveyed clear heights.
Central Shoring & Custom Apex Stubs: Erect `Ring-1` on temporary central shoring at $+9,117 ext{mm}$ plumb to true center. Custom-fit the apex transition stubs to ensure pure radial equilibrium.