Uplifts and excessive bearing pressures in mat foundations
To check for lifts and excessive stresses in foundation slabs, after analysing the structure, open the "Results" tab and select the desired group. Then open the "Envelopes" menu at the top of the interface.
The menu options that allow you to view the aforementioned information are as follows:
- Uplift in mat foundations
- Excessive bearing pressures in mat foundations
Each of these features is detailed below.
Uplift in mat foundations
This option provides information about "Uplifts in mat foundations", if applicable.
If there has been no lifting at any point on the slabs in the group, this is indicated by a warning.
In the event of uplifts, the points on the mesh that have this problem in any combination of scenarios will be marked with red circles.
To find out the uplift value, click on them to display the value of "Maximum upward vertical displacement".
| Note: |
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| In the analysis performed by the program, the slab is discretised in the form of a grid, which is solved using matrix methods. A spring is placed at the intersection nodes of the grid bars, whose constant is the product of the ballast coefficient and its area of influence or tributary. If detachments occur, the springs that link the mesh nodes to the ground in the model would be acting in tension. As the ground cannot work under tension in these cases, if this circumstance occurs, the calculation result is inaccurate, so it is necessary to avoid the existence of detachments. To do this, weight can be added to the slab or the distribution of loads on the ground can be modified, increasing the depth of the slab to make it more rigid or by redesigning the structure. |
Excessive bearing pressures in mat foundations
This option allows you to consult the "Excessive bearing pressures in mat foundations".
If the permissible stress of the ground has not been exceeded at any point on the slabs in the group, this is indicated by a warning.
In the event of excessive tension, the points affected by this problem are marked with red circles.
To find out the value of the "Maximum bearing pressure" at a specific point on the foundation slab, click on that point.
