Spread of point load in wall

[Nigel Lewis]

Hi, I am working out the load on an existing foundation in a bungalow.

I know the weight of the wall and floor etc which are on the foundation but my problem is with the point load from a steel beam which I have designed with Superbeam.

How is the point load dispersed or spread through the wall. For example if the point load is 17.5KN and the wall is 3.6m high from top of concrete to top wall/beam position, what would the loading be for the worst 1m of foundation directly beneath the point load?

[Tony Bryer]

The general rule, assuming that the layout allows it, is to assume that a concentrated load spreads out as a equilateral triangle below the load, so in your case the load ends up being spread over a 3.6m length of foundation. If there are openings or the load is applied near the end of a wall then this assumption will need to be modified accordingly.

[John Cranna]

I have always taken a 45 degree spread from a point load down the wall and thus if the load is 3.6 m up from the footing then it wil spread over a length of 7.2m (3.6 m each side). I would be interested to see if other people go by this or by Tony's principle.

John Cranna

[Tony Bryer]

Yes, on reflection I have assumed 45 degrees in the past. The 60 degree (equilateral triangle) figure comes from Eurocode 6 EN-1996-3 4.3.

[sadmemories20]

I know the weight of the wall and floor etc which are on the foundation but my problem is with the point load from a steel beam which I have designed with Superbeam.

[Tony Bryer]

I know the weight of the wall and floor etc which are on the foundation but my problem is with the point load from a steel beam which I have designed with Superbeam.

I don't wish to sound unhelpful, but if you are going to use any of our programs for real-life projects you do need to be able to accurately assess the loads on members and understand how these are entered in the program being used.