Load Take Down

Load take down is the transferring process of the loads cumulatively to the vertical members below.

Load take down of area loads in the same load class is calculated as follows;

→ The loading area within the boundaries of the tributary area of column is determined at each floor ( if exists )

→ This intersection area is multiplied by the loading value (in psf)

→ The calculated loads on each floor(in kips) are reported cumulatively at each floor depending on their load class in Tributary Forces spreadsheet

Load take down of line loads in the same load class is calculated as follows;

→ The length of line load within the boundaries of the tributary area of column is determined at each floor (if exists )

→ This length is multiplied by the loading (in k/ft)

→ The calculated loads on each floor(in kips) are reported cumulatively at each floor depending on their load class in Tributary Forces spreadsheet

Point loads modelling on slabs mostly occurs at regions where column load transfer from columns above to the slab/beam below.

Before the load take down, distribution factors for the columns near to point load must be calculated.

Distribution factors are determined as follows;

→ Tributary areas of columns near to point load are determined as illustrated in Figure 1

Figure 1

→ A second tributary area calculation is performed by assuming the point load as a column as illustrated in Figure 2

Figure 2

→ The intersection areas of the tributary area of point load and the first tributary areas of the columns are determined as illustrated in Figure 3

Figure 3

→ Intersection ratio is calculated as the intersection area divided by the tributary area of point load

→ The distribution factor for each column is equal to intersection ratio

Load take down of point loads which are in the same load class is calculated as follows;

→ Distribution factor of the column is multiplied by the value of the point load at each floor ( if exists )

→ The forces (in kips) are reported cumulatively at each floor depending on their load class in Tributary Forces spreadsheet

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