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Control test of PcP. stair treads - top flange
Source:
BS/EN ISO 14122-1,2,3
Partial coefficients(Safety)
Safety on load
(acc.to DS 409: 1998): 1.3
(ultimate limited state)
Safety on materials
(acc.to DS 409/412): 1.17
(ultimate limited state)
Permissible deformation
(acc.to DS 412): Span / 200
(Serviceability state)
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BS EN ISO 14122-3:
"Safety of machinery - Permanent means of access to machinery - Part 3: Stairways, ladders and balustrades", states concerning stair treads:
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4. |
General safety requirements concerning materials and dimensions
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4.1 |
The materials and dimensions of constituent elements and construction mode used shall meet the safety objectives of this standard
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4.2 |
The materials used shall be, themselves, by their nature or by a complementary treatment, able to resist corrosion provoked by the surrounding atmosphere.
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4.3 |
Any parts liable to be in contact with the users shall be designed so as not to hurt or hinder (sharp corners, welds with burrs, rough edges, etc.).
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4.4 |
Steps and landings shall offer satisfactory slip resistance to avoid any risk of slipping.
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4.7 |
The structure and the steps shall be designed to satisfactorily resist the intended imposed loads.
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4.7.1 |
For the structure the unfactored loads used in the industrial field, may vary from 1,5 kN/m2 for low density pedestrian traffic without load, up to 5 kN/m2 for low density pedestrian traffic with load or for high density pedestrian traffic.
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4.7.2 |
Steps shall resist the following unfactored loadings:
If the width w < 1200 mm, then 1,5 kN shall be distributed over an area of 100 mm x 100 mm where one boundary is the leading edge of the nosing applied at the middle of the stair width;
If the width w ≥ 1200 mm, then respectively 1,5 kN shall be distributed simultaneously over each of the 100 mm x 100 mm areas applied at the most unfavourable points spaced at intervals of 600 mm where one boundary is the leading edge of the nosing.
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The deflection between the structure and the steps under an unfactored load shall not exceed 1/300th of the span or 6 mm whichever is the lesser. |
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