Strip footing

Definition

A strip footing is a type of shallow foundation that is designed to support continuous loads along a line, typically used for walls or rows of columns. This foundation type spreads the load from the structure over a larger area of soil, reducing pressure and minimizing the risk of settlement. It’s particularly effective in providing stability for structures with long, linear loads.

5 Must Know Facts For Your Next Test

1. Strip footings are often used for residential buildings where walls carry vertical loads, offering a practical and economical solution.
2. They are usually constructed from concrete, and their width is designed based on the load they need to support and the bearing capacity of the soil.
3. The depth of strip footings is critical; they must be placed below the frost line in colder climates to prevent heaving during freeze-thaw cycles.
4. Strip footings are advantageous in that they can be easily formed and poured in place, allowing for quicker construction compared to more complex foundation types.
5. Proper drainage and waterproofing are essential around strip footings to prevent water accumulation, which can lead to soil weakening and structural issues.

Review Questions

• How does the design of a strip footing contribute to its effectiveness in supporting long linear loads?
  • The design of a strip footing is crucial for its effectiveness because it distributes loads evenly along its length. By spreading the weight of walls or columns over a wider area of soil, it reduces pressure on any single point, minimizing the risk of settlement or structural failure. The continuous nature of strip footings allows them to handle the forces from walls or rows of columns effectively, making them an ideal choice for many building types.
• Discuss the advantages and disadvantages of using strip footings compared to other types of shallow foundations.
  • Strip footings offer several advantages, including ease of construction and cost-effectiveness for supporting long linear loads like walls. However, they may not be suitable for all soil conditions; if the soil has low bearing capacity, deeper foundations might be necessary. Additionally, while strip footings are effective in distributing loads, they can be more susceptible to issues related to water accumulation and frost heave if not properly designed and maintained.
• Evaluate the impact of soil bearing capacity on the design and implementation of strip footings in different construction scenarios.
  • Soil bearing capacity is a critical factor influencing the design and implementation of strip footings. In scenarios where soil has high bearing capacity, strip footings can be designed with less width, optimizing material usage. Conversely, in areas with low bearing capacity, wider or deeper footings may be required to prevent excessive settlement or failure. This evaluation highlights the importance of thorough geotechnical investigations before construction, ensuring that the selected foundation type aligns with site-specific soil conditions.

Related terms

Shallow Foundation: A foundation type that transfers building loads to the soil at relatively shallow depths, typically less than 3 meters.

Load Bearing Capacity: The maximum load that a foundation can support without risk of failure or excessive settlement.

Settlement: The downward movement of the ground caused by the loading of structures, which can affect the integrity and performance of a building.