Caluculation help for Load tables

Loading

In order to be able to choose the right type and dimension of grating it is important to know the loading that the grating will be subjected to. Below and on the following pages are extracts from load tables and descriptions of some simple rules.

Load group	Calculated loading to NR
Dwelling load (domestic rooms etc.)	2,0 kN/m²
Small gatherings (classroom, restaurant etc.)	2,5 kN/m²
Large public gathering (department store, exhibition hall, stands with seats etc.)	4,0 kN/m²
Heavy loading (Terraces, light industry)	5,0 kN/m²

Calculation of Load

If grating type, span width and uniformly distributed load are known, the load permitted related to the deflection permitted (1/200 of the span width) from the following formula:

Qpermitted	= Qmax / f x fpermitted
Qpermitted	= uniformly distributed load permitted
Qmax	= maximum load permitted according to table
f	= deflection at Qmax (according to table)
ftill	= 1/200 of span

Load alternatives

For all tables the conditions stated below apply. To the left of the boundary lines the deflection is less than 1/200 of the span width at 5 kN/m2 uniformly distributed load. An approximate guide for point loading can be obtained from part of linear loading.

Example:
Point loading Ø 100 mm. Take 1/10 value of the linear loading.

Q = uniformly distributed load allowed for (kN/m²)
f1 = deflection at Qmax / deflection at 5 kNm² (mm)
P = linear load allowed for
f2 = deflection at Pmax (mm)