The floor plan shown below is for a flat slab that is supported by square columns of 350mm sides. The distances between the grids are X1, X2 and Y1, Y2. The values of these distances are to be taken from the last 4 digits of your
X1 = 9m, X2 =7m, Y1 = 9m, and Y2 = 4m. The centre of the internal columns coincides with the intersection point of the grids. The structural engineer decided to use concrete grade C40/50, but is not sure about the appropriate thickness of the slab that is sufficient to resist the punching shear failure without the need to use shear reinforcement.
Use the finite element (FE) software, MIDAS Gen, or any other FE software to:
1- Create an FE model for the slab.
2- Carry out an FE analysis, considering the boundary conditions that are provided by the columns, and the permanent and variable loads as below.
Data: Characteristic permanent loads: self weight plus 1.7 kN/m2 for partitions.
Characteristic variable load: 4 kN/m2
Assume the building is braced against wind loading.
Slab thickness: find the smallest thickness, rounded to the nearest 25mm, such that the vertical deflection does not exceed the permissible limit of EC2.
Pattern loading on the slab must be considered, but not the flexural stiffness of the columns.
Output: you are required to produce a 1000 words technical report that includes the following:
A plan of the geometrical model.
Contour lines of deflected shape, bending stresses and shear stresses.
A table showing maximum deflections against different slab thicknesses.
Explanation about the loading used.
Recommendation on the smallest slab thickness to use, and the reasoning behind it.
Extra marks may be gained by showing the effect of refining the mesh.
A brief comment on how safe this thickness is against punching shear attracts extra marks.