Foundation Engineering

Foundation Engineering is a branch of civil engineering that deals with the design and construction of foundations for structures of all types and sizes. The main goal of foundation engineering is to transfer the load of a structure to the soil in a safe and stable manner. In this explanation, we will discuss some of the key terms and vocabulary related to foundation engineering in the context of the Postgraduate Certificate in Geotechnical Engineering & Soil Mechanics.

Soil Mechanics: Soil mechanics is the study of the behavior of soil under various conditions, such as loading, unloading, and changes in moisture content. It is a fundamental discipline in geotechnical engineering, as the properties of soil play a critical role in the design and performance of foundations.

Bearing Capacity: Bearing capacity is the ability of the soil to support the weight of a structure without failing. It is usually expressed in terms of the ultimate bearing capacity, which is the maximum load that the soil can support, and the allowable bearing capacity, which is the maximum load that can be safely applied based on factors such as settlement and soil strength.

Settlement: Settlement is the downward movement of a structure due to the compression of the soil beneath it. Settlement can occur gradually over time, or it can be rapid and catastrophic. The amount of settlement that a structure will experience depends on the properties of the soil, the load of the structure, and other factors.

Shallow Foundations: Shallow foundations are foundations that are located near the surface of the ground, typically no more than a few meters deep. They are used for structures with low loads, such as houses and small buildings. Shallow foundations can be further classified into spread footings, strip footings, and raft foundations.

Spread Footings: Spread footings are shallow foundations that are used to support vertical loads from columns or walls. They are typically rectangular or square in shape and transfer the load of the structure to a large area of soil.

Strip Footings: Strip footings are shallow foundations that are used to support linear loads from walls. They are typically rectangular in shape and transfer the load of the wall to a long strip of soil.

Raft Foundations: Raft foundations are shallow foundations that cover the entire footprint of the structure. They are used for structures with large loads or where the soil conditions are poor. Raft foundations distribute the load of the structure over a large area of soil, reducing the pressure on the soil and minimizing settlement.

Deep Foundations: Deep foundations are foundations that are located deep below the ground surface, typically more than a few meters deep. They are used for structures with high loads, such as skyscrapers and bridges. Deep foundations can be further classified into driven piles, drilled shafts, and augercast piles.

Driven Piles: Driven piles are deep foundations that are installed by driving a steel or concrete pile into the ground using a pile driver. They are used in a variety of soil conditions and can be installed quickly and efficiently.

Drilled Shafts: Drilled shafts are deep foundations that are installed by drilling a hole in the ground and filling it with concrete. They are used in stable soil conditions and can reach depths of up to 100 meters or more.

Augercast Piles: Augercast piles are deep foundations that are installed by drilling a hole in the ground using an auger and then filling it with concrete. They are used in unstable soil conditions and can be installed in a variety of soil types.

Geotechnical Engineering: Geotechnical engineering is the application of soil mechanics and other disciplines to the design and construction of foundations, retaining walls, tunnels, and other civil engineering works. It involves the study of the physical and mechanical properties of soil and rock, as well as the interaction between these materials and the structures built upon them.

Site Investigation: Site investigation is the process of collecting and analyzing data about the soil and rock conditions at a site where a foundation or other civil engineering work is to be built. It involves drilling boreholes, collecting soil and rock samples, and performing laboratory tests to determine the properties of the soil and rock.

Soil Exploration: Soil exploration is a component of site investigation that involves the drilling of boreholes and the collection of soil samples for laboratory testing. It is used to determine the stratigraphy, or layering, of the soil, as well as its physical and mechanical properties.

Standard Penetration Test (SPT)