What are the conditions to be satisfied during the design of a combined footing?

Then the equation of the bidirectional bending is used to obtain the stresses acting on the contact surface of the combined footings, which must meet the following conditions: 1) The minimum stress should be equal to or greater than zero, because the soil is not capable of withstand tensile stresses, 2) The maximum …

When the column lies on the property line which type of footing is preferred?

Strap footing
Strap footing is an alternative method of providing combined foundation connecting column located on property line and the interior of the building. In the case of strap footing, independent slabs are provided below the columns, connected by strap beam.

When two or more columns are supported by a footing?

When two or more columns are supported by a footing if is called combined footing. This footing may be of rectangular or trapezoidal in plan.

What are the considerations in designing combined footings?

The foundation of a combined footing must not undergo excessive settlement or shear failure, and the footing itself must be strong enough to resist the bending moment and shear forces as a result of the superstructure load. The thickness of combined footings is usually governed by shear force considerations.

Which of the following statement is correct in a combined footing for two columns carrying an unequal load the maximum hogging moment occurs at?

The maximum hogging Bending moment will occur between W1 and W2 where shear force is zero. We get that at, ∴ Bending Moment is maximum nearer to the less loaded column for the unequally loaded columns where SF is zero, and at equidistant from either column for the equally loaded column.

Where do you provide a combined footing?

Combined footing is used while construction of two or more columns when they are close to each other and their foundations overlap. The main purpose of using combined footing is to distribute uniform pressure under the footing.

What are forces to be considered while designing the footings?

Foundations in sand and silt deposits Placing the footing at a sufficient depth that the soil beneath the footing is confined.