Technical Report #3 - A two page (300 words) report about "Drilled Shaft Foundations types and methods". Your report should include charts/tables and other tabulated information collected from your...

Drilled Shaft Foundations - Types and Methods
Drilled Shaft Foundations- Types and Methods
Drilled Shaft Foundations are a type of substructure foundation. They are essentially cylindrical shafts that are excavated into the earth and then filled up with resteel and concrete. They support loads through friction between the concrete and the adjacent soil. Their sizes range between 30 inches to 72 inches in diameter and have the capacity to extend about 50 inches or more into the ground. (Huat & Pavadai, 2006)
Drilled Shaft requirements
When using drilled shafts several considerations need to be kept in mind. The first being a rigorous inspection with an initial plan review. The construction of drilled shaft foundations must always be undertaken by experts who can address problems as and when they arise.
Drilled shafts need steel casings to assist in shaft excavation. This is done through rolling and welding a steel plate to form a large diameter pipe. Casings can be placed before after or during the excavation. They usually have teeth at the bottom end allowing optimum anchoring of the casing and fitting into the soil.
Different types of drilled shafts or piers
Drilled piers can broadly be classified into four types. Even though these four types are similar in their construction there are essential differences in their design assumptions, load bearing mechanism and load transfer to adjacent earth mass. The types are -
1. Straight-shaft end-bearing piers
Straight-shaft end-bearing piers gain all their support from the strong soil located at the bed of the ground. The upper level soils are in no way effective at providing support to the load on the pier. (Fig.-1).
Fig-1-straight shaft end bearing pier (Hazelton, 2015)
2. Straight-shaft side wall...