Titel_SS06

Wind Load Snow Load

Transient Load

Sustained Load

Permanent Load

Figure 7.1: Loads on buildings.

In the following a probabilistic model for each of the loads illustrated in Figure 1 will be
given.

Permanent Loads

The permanent loads acting on a structure consists of the self weight of structural and non-
structural members. The latter is also often referred to as the dead load. The name permanent
load indicates that the load is varying insignificantly over time; however, its intensity is
uncertain.

The permanent load due to the self weight G of a structural component with volume V may
be assessed by

V

GdV 6 (7.1)

where 6 is the density of the considered material.

Following JCSS (2001), the uncertainty associated with the self weight of steel components is
predominantly due the uncertainty in the cross-sectional area. Both the density and the length
dimensions of structural members made of steel may be assumed deterministic.

For structural components made of concrete and timber the uncertainty associated with the
density is dominating. Representative values for the coefficient of variation for steel, concrete
and timber materials are given below in Table 7.1.