Ground Engineering and Foundations – A Look Behind the Scenes

Sunday - April 30 2023, 08:36 UTC - 1 year ago

Ground engineering is an essential part of building construction, involving thorough analysis of the soil and rock conditions at a building site to design foundations, retaining walls, and other structures that will support the weight of the building and resist the forces of nature and other factors. Ground engineers use a variety of methods and theories  to do this, and pile foundations are the most likely for structural support in deep foundations.

Imagine you're building a sandcastle on the beach. You carefully sculpt the walls and towers, and everything seems perfect. But then, as you build taller and taller, the sand shifts, and the structure wobbles. Without a solid foundation, your sandcastle is in danger of collapsing.

Well, it's the same thing with buildings – without a strong foundation, they can't stand up to the forces of nature and the weight of the structure itself. That's where ground engineering comes in.

Ground engineering is like building a solid, sturdy base for your sandcastle – but on a much larger scale. By analyzing the soil and rock conditions at a building site, ground engineers can design foundations, retaining walls, and other structures that will support the weight of the building and resist the forces of wind, water— and even natural disasters— over time.

Ground engineers (as well as soil engineers) use various techniques and methods to investigate a site's soil and rock conditions and design foundation structures appropriate for the site's specific geological and environmental conditions. One such structure, a pile foundation, involves driving long, slender columns (called piles) into the ground to support structures by transferring loads from the structure to the ground. But other foundation types can be used - depending on conditions and the type of building.

To dig deeper, Interesting Engineering (IE) reached out to Steve Hadley— Chair of the Federation of Piling Specialists and Managing Director of Central Piling.

--- Buildings with large loads require deep foundations --- .

Hadley clarified that understanding how soils behave is critical to practicing ground engineering. It involves developing solutions to retain soils as well as maintaining the structures built within and on top of them.

"A good quality ground investigation is crucial for any successful ground engineering project," he said.

To elaborate, a ground investigation is a thorough and accurate analysis of a site's soil, water, and rock conditions, which provides the data and information necessary for designing and building safe, stable, and durable structures.

It involves comprehensive data collection methods, such as soil sampling, drilling, geophysical surveys, and laboratory testing, followed by data analysis and data interpretation by qualified professionals.

"Where the ground is strong close to the surface level, then for conventional low-rise structures such as a house, it may be possible to have a trench foundation as shallow as one meter deep," he said.

Trench-fill foundations typically involve excavating a narrow strip of soil, which is then filled with concrete to create a level base for the building. The width and depth of the trench depend on factors such as the size and weight of the building, the soil conditions, and the local building codes.

--- "A pile is effectively a column of timber, steel or concrete" --- .

"However, for more complex conditions such as large vertical loads from a tower block, horizontal forces from wind, or tensile forces from clay heave (swelling), deeper foundation depths will be needed," Hadley explained.

"The most efficient way to do this is via a pile. A pile is effectively a column of timber, steel or concrete, typically over one meter in diameter, and drilled or driven into the ground until the appropriate bearing strata (rock or soils) is found." .

In some cases, piles may be used with pile caps— large concrete blocks at the top of a pile, which can support and distribute the loads evenly.