Definition

A strip continuous footing, also known as a continuous footing, is a type of shallow foundation that provides support along the length of a load-bearing wall or series of columns. It is typically a long, narrow strip of reinforced concrete that spreads the load of the structure it supports over a wider area of soil. This type of footing is commonly used in buildings where walls carry most of the structural load, such as in residential and commercial construction.

Construction

The construction of a strip continuous footing involves several key steps:

• Site Preparation: The site is cleared and leveled, and the trench for the footing is excavated along the line of the load-bearing wall or columns.
• Reinforcement Placement: Steel reinforcement bars are placed within the trench to provide additional strength to the concrete footing. The reinforcement is typically arranged in a grid or cage pattern.
• Concrete Pouring: Concrete is poured into the trench over the reinforcement, filling the entire length of the trench. The concrete is then compacted and leveled to ensure a uniform and stable foundation.
• Curing: The concrete is allowed to cure and gain strength over a period of time before the construction of the wall or columns begins.

Context of Use

Strip continuous footings are commonly used in various geotechnical and structural engineering applications, including:

• Residential Construction: In residential buildings, strip continuous footings are often used to support load-bearing walls and provide a stable foundation for the structure.
• Commercial Buildings: These footings are also used in commercial structures where walls or closely spaced columns carry the majority of the load.
• Retaining Walls: Strip continuous footings are used to provide stability and support for retaining walls, ensuring they can resist lateral earth pressures.
• Low-Rise Buildings: In low-rise buildings, strip continuous footings are a cost-effective and efficient solution for distributing structural loads over a larger area of soil.

Advantages

• Cost-Effective: Strip continuous footings are relatively simple to design and construct, making them a cost-effective solution for many types of buildings.
• Even Load Distribution: These footings distribute the load of the structure evenly along the length of the wall, reducing the risk of differential settlement.
• Suitable for Varied Soil Conditions: Strip continuous footings can be adapted to a range of soil conditions by adjusting the width and depth of the footing.
• Versatile: They can be used in a wide variety of structures, from residential houses to commercial buildings, making them a versatile foundation option.

Limitations

• Limited to Shallow Foundations: Strip continuous footings are generally used for shallow foundations and may not be suitable for very tall or heavy structures that require deep foundations.
• Soil Bearing Capacity: The effectiveness of a strip continuous footing depends on the soil’s bearing capacity, which must be sufficient to support the load without excessive settlement.
• Potential for Cracking: If not properly designed or constructed, strip continuous footings may crack due to uneven loading or poor soil conditions.

Summary

Strip continuous footings are a fundamental and widely used type of shallow foundation that supports load-bearing walls and columns by distributing the structural load over a larger area of soil. These footings are cost-effective, versatile, and suitable for a range of building types, from residential homes to commercial structures. However, their use is generally limited to shallow foundations, and their effectiveness depends on the soil’s bearing capacity and proper construction techniques. When designed and built correctly, strip continuous footings provide a stable and reliable foundation for many types of buildings.