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# Buttresses

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# Buttresses

CALCULATION OF WALLS IN THE PRESENCE OF BUTTRESSES

The case of buttress walls requires the insertion of geometric data, i.e. thickness and longitudinal interaxis. The buttress can be placed inside (ground side) or outside.

The height of the buttress is assumed equal to the height of the wall itself, while the base is placed equal to the length of the shelf of upstream foundation, for internal buttresses, downstream, for external ones.

The calculation of the thrust on the wall is independent of the presence of the additional element and is carried out with the same procedure as for the corbel wall.

The presence of the buttress has an effect, with the weight force, both in terms of stress on the shelf in elevation, and in the global checks to tipping, limit load and sliding.

The weight force of the buttress is counted in the resulting Fy of the stresses on the wall, as well as an external force, but does not appear in the load conditions of the Calculation Menu: this implies that it is not possible to assign to it a combination factor other than unity.

Verification of the section in c.a. and armor calculation

At each calculation section along the height of the wall, the program considers the T-check section as an equivalent rectangular section with equal moment of barycentric inertia.

That is, the section a T with dimension B equal to the center distance of the buttresses is assimilated to an equivalent rectangular section of width equal to 1 m and height Hequ such that the moment of barycentric inertia of the two sections is equal.

With this assumption, the equivalent rectangular sections are designed and verified.