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How-to build a brick masonry staircase on a flat arch in 38 picturesProject: Amar Bari at Santiniketan (2007-2009)Client: Bengal GreenfieldArchitect: Dulal Mukherjee

Working Drawings by: Laurent Fournier1. InspirationsSarrasin Vaults Hassan Fathy

Construction of a staircase onvoute sarrasine in France withhollow clay tiles and Gypsum-(Plaster of Paris) by Pierre-jeanGehannin - http://www.gehannin-marbre-carrelage.com/

Nubian vaults built with adobe inEgypt (in Gourna: a Tale of TwoVillages, by Hassan Fathy)

2. Construction sequence

1. Basic equilibrium 2. Cross-section through the stairs

7/27/2019 A Brick Masonry Staircase in 38 Pictures

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3. Algebraic checking: load 4. Assumptions, reactions 5. Equilibrium

6. Checking the first landing 7. Equilibrium at the wall base 8. Bottom slab reinforcement

7/27/2019 A Brick Masonry Staircase in 38 Pictures

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7/27/2019 A Brick Masonry Staircase in 38 Pictures

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16. Second Nubian vault 17. Closing the Nubian vault 18. Day 2: Marking the steps

19. Shuttering 20. Starting the flat arch 21. Second layer

22. Notice the camber of the ply 23. Third layer 24. 12 th layer

25. Starting the other side 26. Notice the steps are completed 27. Shifting side again

7/27/2019 A Brick Masonry Staircase in 38 Pictures

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28. End of the second day (with line of thrust superimposed on the photograph)

29. Joining the two sides 30, 31. Two masons and one helper are required for the entire staircase

32. Closing the pointed arch 33. The third Nubian vault 34. Closing the vault

7/27/2019 A Brick Masonry Staircase in 38 Pictures

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7/27/2019 A Brick Masonry Staircase in 38 Pictures

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3. References

Galileos parallelogram of forces and Epure de Mry (Above fromArthur Vierendeels cours de stabilit des constructions, 1907)

Jacques Heyman: The StoneSkeleton, 1966, Cambridge 1995

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Heyman summarizes his mastersafe theorem of plasticity as:

if the designer can find a way inwhich the structure behaves

satisfactorily, then the structureitself certainly can.

Tip for flat arches:Despite Heymans assumption of infinite strength of masonryelements, when tracing the line of thrust for checking againstultimate load in flat arches, it isimperative to remain within the

middle half , to avoid failure bycrushing of the material (outline of proof on the left).

As usual, try to keep the line of thrust within the middle third forservice load.

In any case always check thestress, particularly when usingbrick or adobe.