Saturday, 24 October 2015

Design of combine Trapezoidal footing

A combined footing supports the load of two or more adjacent columns. Such a footing is provided under the following circumstances:

1) When the columns are very near to each other so that there footing overlap.
2) When the bearing capacity of soil is less, requiring more area under individual footing.

3) When the end column is near a property line so that its foting cannot be spread in that direction.
A combine footing may be rectangular or trapezoidal in plan. The aim is to get uniform pressure distribution under the footing. for this the CG of footing are should coincide with the CG of the combine loads of the two columns. There are four types of combine footing commonly used.
1) Combine rectangular footing
2) Combine trapezoidal footing
3) Strap beam footing
4) Raft footing.

This numerical is of combine trapezoidal footing must watch and download pdf to better understand.