It is possible to design the floor slab or raft
foundation for punching due to concentrated loads and
reactions from columns, piles or supports. The design
for punching is carried out according to 4 different
codes: ACI, DIN 1054, EC2
For rigid and elastic rafts, it is convenient to determine the flexibility coefficient of interior node at the characteristic point of the loaded area on that node. While for flexible foundation, it is real to determine the flexibility coefficient of interior node at that node.
Now it is possible to determine the flexibility
coefficient of the interior node due to a uniform load
at that node Figure B-3
at the characteristic point of the loaded area,
where rigid settlement equal to flexible
at the midpoint of the loaded area, where
maximum settlement occurs.
at the interior node on the loaded area.
Flexibility coefficients for exterior nodes
Earlier versions of ELPLA determine
flexibility coefficients for both interior and exterior
nodes by assuming uniform loaded areas on these nodes.
This assumption uses the principle of superposition for
determining the flexibility coefficients. Now it is
possible to convert the loaded areas on exterior nodes
to point loads, Figure B-3. By this way the program
doesn't need to use the principle of superposition in
the analysis, making it much faster than the old
analysis. The new way of analysis is consequently faster
and more efficient for problems that contain a large
finite element mesh.