If depth of the footing is equal to or greater than its width, it is called deep footing, otherwise it is called shallow footing. The depth of foundations of adjacent buildings.įootings may be classified as deep or shallow.The bearing capacity of the underlying soil.The type of footing chosen for a particular structure is affected by the following: Overturning loads are frequently created by horizontal loads placed above the footing’s base. The footing must be stable enough to withstand overturning loads.The footing must be strong enough to withstand slide due to any horizontal loads.Due to applied loads, the calculated settlement of the footing must be less than the permitted settlement.Bearing pressures are measured in pounds per square foot or other units of force per unit area. Bearing pressures are the forces exerted by the footing on the supporting soil. Calculated bearing pressures must be lower than permitted bearing pressures.The foundation shape is chosen such that any minimal requirements based on soil factors are met.This stage is frequently accomplished with the assistance of a Geotechnical Engineer. Choose a footing arrangement and establish the soil specifications that are required.Determine the footing requirements, including the loading and nature of the supported structure.The following steps are commonly taken while designing a footing: When the soil is very strong, the footing must not be wide in order to hold the building up. The footing size is important because it transmits the load into the soil.Īs a general rule, when the the bearing capacity of the soil is lower, the footing needs to be wider. NOTE: The footing size will depend on two things: One is the strength of the soil and two is the the weight of the building. The size of the footing should be able to hold the weight it is needed. If the footing is too large, it may waste money and space because it may take up more room than necessary while not supporting the weight it is supposed to. The right size of the column footing is important because, if the footing is too small, the columns may not be able to support the weight they are meant to hold up. If the soil type is hard and compacted, then the engineer may choose a smaller footing sizeĪ footing can be used for various reasons, such as to help support a building as it’s being built or to help support a building or other structure when there is no more ground to stand on.Īs mentioned above, the size of a footing is determined by the size of the building or structure, and it can vary from as small as 2 square feet to as large as 1000 square feet. The type of soil on which the building is to be constructed is also taken into consideration. This might require the engineer to adjust the footing size in order to achieve an appropriate depth for the footing. In order to ascertain a column footing size for the construction of a particular building, the engineer must take into consideration a few thingsįirstly, the size of the building is important. Where differential settlement is a possibility, the different footings should be designed in such a way that they settle independently of each other.Ī soil analysis is used to determine the best type of foundation, and a structural design is used to estimate footing dimensions and the amount of reinforcement needed.īecause the soil’s compressive strength is often significantly lower than that of concrete, the contact area between the soil and the footing is much larger than that of the columns and walls. The settlement is determined by the severity of the load, the kind of soil, and the foundation level. they designed to transmit these loads to the soil without exceeding its safe bearing capacity, to minimize settlement of the structure, to minimize differential settlement, and to prevent sliding and overturning. A lot of factors go into determining the footing size.įootings are structural members that carry column or building loads to the soil beneath the structure. In architecture, the footing size of a column is the length and width of the base or measure of the area in square feet that rests on the ground for the foundation.