1) The document discusses the structural challenges of supporting the irregularly shaped mosque ceiling or "peel". 2) Several proposals were considered to support the peel addressing clashes with ducts and walkways, including vertical hangers and building secondary steel grids. 3) The chosen solution was to build secondary steel grids supported by the main steel to form platforms above the peel, ducts, and walkways, using U-bolts and rods to allow for movement. 4) Supporting the irregularly shaped sides of the peel, especially the east side where no other structure existed, also posed challenges addressed through introducing a steel structure on the second floor extending up.

1. Presented to you by
Structural Engineer
Mohamed Galal Mohamed Nour El Din
2014
QATAR FACULTY OF ISLAMIC STUDIES
QFIS and structural challenges
Mosque secondary steel

2. Introduction :-
-I would like to extend my thanks first to Allah who gave me the chance to work
in this project and second to our management who believed in me.

3. Mosque Peel Support
What is Mosque peel and were it is located in the project
Mosque peel is a doubly curved shell irregular in shape as shown in photo
Located at first floors and part of second floor extending up to 19 m height.

4. Mosque Peel from inside

5. Mosque Peel Support
The peel itself consists of two intersected stiffeners 50X3 mm and these
stiffeners connected to each as shown then covered from below with a wire
mesh which will be covered by Gypsum later to form the last finishing surface
appears to the prayers from the prayer hall (Mosque).
This proposal was suggested by Mr. Nicola Saab instead of the IFC design
heavy T-sections and published in our knowledge management recently
Under presentation called “ Constructability “
Notches in stiffeners used to collect them

6. Mosque Peel Support
We have divided the peel into two part during our studies
1.Mosque Peel Support-PART 1- Mosque roof. (48m width X 35 m length)
2.Mosque Peel Support-PART 2-The mosque sides.
Fist Side E1 occurs at the North side 32m width X 9 m height.
Second Side E3 occurs at the west side 34width X 12 m height.
Third Side E1 occurs at the South side 36m width X 17 m height.
Last Side occurs at the East side 45m width X 19 m height.

7. Mosque Peel Support

8. Mosque Peel Support
-The designer introduced a notional design to support the Mosque roof only
This design was non executable since they depended only on a vertical hangers
(rods) will be fixed to main steel with length 6 m passing through
A grid of MEP. Ducts and service walkway.
-Using hangers with length 6m will create a loose support “stiffness condition”
-Distance between main steel were 3 m (peel has to carry itself in this span
between hangers)
-The designer refused later to fix the hangers which he designed to service
walkway or passing it though MEP. Duct using sealed conduit.

9. Supporting system as per IFC

10. Clash type (1) - As shown we will have a clash with the
service gantry

11. Clash type (1) - Snapshot from our BIM Model showing
the clashes with vertical rods with the service gantry

12. Clash type (2) -Snapshot from our BIM Model showing the MEP
ducts. If we used the rod system we will clash with ducts

14. Mosque Peel Support
We started our journey by studying & inventing more than one solution
And measure the advantages and disadvantages for each solution suggested
through brain storm sessions.
We have to consider the following factors during this hard journey.

15. Mosque Peel Support
First proposal

16. Mosque Peel Support
Second proposal

17. Mosque Peel Support
Second proposal

18. Mosque Peel Support
Third proposal

19. Mosque Peel Support
Third proposal

20. Mosque Peel Support
Sine main steel bottom flange more than 50
mm Clamps can’t be installed to this
thickness-> We went for welded hangers.
Fourth proposal

21. Mosque Peel Support
Fourth proposal

22. Mosque Peel Support
Swivels and clamp system were very
expensive so we went for welding the
hangers directly to main steel & build a
grid of secondary steel below and
bridging the MEP. Ducts & walkway level
but above peel level to allow for fixing
the U-bolts and rod system
Fifth proposal

23. Mosque Peel Support
Fifth proposal
Due to the wisdom and experience of our Management we went to the fifth
proposal because of the following reasons
a. System is very cheap compared to other systems from HILTI.
b. Workers will use the secondary steel grid as a scaffolding during erecting the
peel system & MEP. Ducts above to minimize the scaffolding height if we build
it from first floor (18m).
C. MEP. will use it as a support for the firefighting system which is very near
from peel level.

24. Decision:-
1.We need to build a support for the MEP. ducts at the level of the main steel
Then MEP. Team will use clamps & rods to hang their ducts but they will need
To use secondary frame surrounding the ducts as shown below.

26. Decision:-
2. We need to build a grid platforms hanged from main steel at a reasonable height
from the peel surface and bridging the gantry & MEP. Ducts (no support should be
attached to gantry or MEP. Ducts as advised by consultant)

27. Challenges:-
1. Due to the holy nature of the Mosque especially in Islamic country like
Qatar we must be very cautious and consider this job as the most critical
element in the project and study all expected loads might affect the
structural system during construction and during its life time .
2.Complixty of the peel shape and irregular distribution of MEP ducts.
( the platforms will be built like steps to match the doubly curved peel)
3. Deflection and movements of main steel and how to avoid transferring these
movements to the peel to avoid cracks in gypsum. ( using a U-bolt with rod will
allow for rotation in X and Y direction and by placing double nut at the top of
the platform stringers we avoided transferring any vertical movement to the
peel.

31. Mosque Peel Support
Turn buckle
To allow site
team to adjust
the levels after
installing the
peel stiffeners
Coupler
Level alignment
will be from the
connection with
secondary steel
Turn buckle
To use this system
you must order right
threaded rod & left
threaded U-bolt or
the opposite.
Coupler
Allows you to join
same threaded
direction for the rod
and the U-bolt.

32. Result : (TYP. DETAIL)
Nut at the top side of the
support only

33. Connection between vertical rods coming from secondary steel grids and the peel
To prevent transferring any movement from main steel to the peel

37. Peel shape from inside the Mosque after cast the Gypsum

38. Mosque Peel Support-Mosque Sides

39. Challenges:-
1. The doubly curved shape of the peel sides.
2. Irregular MEP. Ducts shapes and distribution.(No rerouting in ducts is
allowed as these routes were designed and under fabrication / installation)
other wise we will end up with
3. Corian screen and its supporting system.(coordination with Subcontractors)
to avoid clashes & claims later.
4. At the east side of the peel there were no element to support our
secondary steel so we have to introduce a huge structure to support this side.
Mosque Peel Support-part 2

40. Mosque Peel Support-part 2

41. Mosque Peel Support-part 2

42. Mosque Peel Support-part 2

43. Mosque- Second Floor
Wall 17 m width & 12 m height
Wall 6 m width & 12 m height
Wall 7 m width & 12 m height
Mosque Peel Support-part 2

44. East system introduced on the second floor extended up 12 m up to fourth
floor level. To cover the Mosque shoe rack, the ceiling of mosque corridor and the
peel
Mosque Peel Support-part 2

45. Mosque Peel Support-part 2
East system introduced on the second floor extended up 12 m up to fourth
floor level. To cover the Mosque shoe rack, the ceiling of mosque corridor and the
peel

46. System were attached to the
Core wall using fixed
connection type to help in
supporting the truss out of
plane direction and the
connections between
members designed as moment
connections to make it a 3D
frame
East system introduced on the second floor extended up 12 m up to fourth
floor level. To cover the Mosque shoe rack, the ceiling of mosque corridor and the
peel
Mosque Peel Support-part 2

47. Mosque Peel Support-part 2
East system introduced on the second floor extended up 12 m up to fourth
floor level. To cover the Mosque shoe rack, the ceiling of mosque corridor and the
peel

48. Red Members carrying the ceiling of the corridor and resisting the loads out of plane
Cyan Members to carry the Peel surface.
Green columns are the main supports and the shoe rack will be build between
them.
Mosque Peel Support-part 2

49. East system introduced on the second floor
reaching up to fourth floor level. To cover the
Mosque shoe rack, the ceiling of mosque
corridor and the peel
System supporting the mosque corridor
(back probed to RC beams to resist lateral
forces.
Mosque Peel Support-part 2

57. Result :

58. Result :

59. Result :

60. Result :

61. Result :

62. Result :

63. Result : East system introduced on the second floor reaching up to fourth
floor level. To cover the Mosque shoe rack, the ceiling of mosque corridor and
the peel

64. Tools used
1.The good utilization of our internal BIM system helped me so much to
accomplish these work. I would like to extend my thanks also to Mr.
Ibrahim Taha who was very helpful during design stage of these items.
2.Getting the 3D Model from BIM.
3.Draw all items using Auto CAD.
4.Sending the members drawn in 3D environment using Auto CAD to BIM
for coordination with other disciplines in the BIM model.
5. Once we are sure there is no clashes. I start design of steel members
(main framing) using SAP2000
Tools and Techniques used to solve these items

65. Tools used
6. After completing the SAP Model I have to choose type of supports and
run the analysis and get the results (Joints deflections , Joints reactions
….ect)
7. Design of connection Using HILTI PROFIS if it is attached to concrete and
manually if it is attached to steel.
8.Finally we rebuild our steel model again using TEKLA to send it to our
subcontractors / steel fabricators to extract fabrication drawings.
Tools and Techniques used to solve these items

66. Tools used
9. Prepare the design drawings/GA/Assembly/ connection
details and insure that we are placing coordinates of the
members ends to avoid any wrong orientation on site later.
Tools and Techniques used to solve these items

67. Tools and Techniques used to solve these items
Techniques
1.First technique to be used “we can do it”
Train your subconscious that you can do it & you can solve the
problem.

68. Tools and Techniques used to solve these items
Techniques
2. Use Deming Cycle

69. Tools and Techniques used to solve these items
Techniques
3. Using to do list technique in order to priorities your work
and don’t not get lost.

70. Tools and Techniques used to solve these items
Techniques

71. Last but not least
I would like to thank our project director
Mr. Mahdi Salem for his support and trust.