Combined Footing

Combined Footing:

Advantage of Combined Footing

The advantage of combined is if there is required two or more columns construed in a small area then we can use combined footing. Another advantage of combined footing is where the load-bearing capacity of the soil is low there we construed combined footing. Where the soil capacity of the Construction area is unequal to distribute the load evenly to the sub-soil we construed combined footing. This is another advantage of combined footing. The common advantage of combined footing is when a column closes the property line and footing is not spread the front of the property line then combined footing help to construct the column. To get uniform pressure distribution under the footing the combined footing is widely used. And help to maintain the center of gravity of the column. This type of combined footing is more profitable than another footing. The combined footing is provided to equally distribute the load to the super-structure to the sub-soil. This is another advantage of combined footing. Because there is a common footing used for two or more columns. So the construction cost of the structure is reduced. The combined footing can be used in the difficult construction sides. Read more

Disadvantage of Combined Footing

The common disadvantage of combined footing is, sometimes the ground-water level is rise. Which causes the loss of contact of soil with the foundation. If the foundation raft thickness is high, the problem may arise due to the heat difference. The footing area is reduced because a common footing is used for many columns. In combined footing, it is difficult to maintain the center of gravity of the columns. The general disadvantage of combined footing is that its size should be varied to the place. Sometimes it's should be made rectangular or sometimes trapezoidal. Read more

Application of Combined Footing

There have been many practical applications of combined footing in our construction field. A combined footing is considered when a column closes the property line and footing is not spread the front of the property line then combined footing help to construct the column. The Dimensions of one side of the footing are determined to some lower value so that column footings may be combined. If the load-bearing capacity of the soil is low, and the area requirement is more under the individual footing. In combined footing, if there are required two or more columns construed in a small area then we can use combined footing. The combined footing is required to intersect a perimeter or grade beam. This type of footing is applied when the proximity of building a line or existing building or sewer, adjacent to a building column. The combined footing is applied when an equal load distribution is required from the structure to the sub-soil. It is applied to the shear force and bending moment calculated at the salient point and then draws the SFD and BMD. It is applied to make a more economical structure Because there is a common footing used for two or more columns. So the construction cost of the structure is reduced. Read more

Types of Combined Footing:

Rectangular combined footing. Trapezoidal combined footing. Strap combined footing. Raft combined footing. Read more

1. Rectangular Combined Footing

3. Strap Combined Footing

When the Combined Footing Is Used?

When two or more columns are supported in a row and a common foundation is called combined footing. The point of application locates the column loads. Such that the pressure of allowable soil does not exceed when computing the area of the footing. The footing such that proportion the resultant the loads pass through the center of the footing. The shear force and bending moment calculated at the salient point and then draw the SFD and BMD. To design the longitudinal steel check the longitudinal shear. The development length check for the longitudinal steel. The longitudinal bars curtail the economy. When draw and detailed the reinforcement and prepare the bar bending schedule. For the longitudinal movement, the reinforcement is placed in the appropriate positions. In the combined footing the footing assumes to rigid and resing on homogeneous soil. In this combined footing the maximum bending moment takes as the design value for the reinforced concrete footing. Read more

Advantage of Combined Footing

The advantage of combined is if there is required two or more columns construed in a small area then we can use combined footing. Another advantage of combined footing is where the load-bearing capacity of the soil is low there we construed combined footing. Read more

Disadvantage of Combined Footing

When the combined footing is used the reinforcement sometimes the groundwater level rises. One of the common disadvantages of combined footing is the size of the footing varies. Read more

Application of Combined Footing

When two columns are very close enough to each other such that their footing overlap. When the load-bearing capacity of the soil is low, the requirement of more area under the individual footing . Read more