Soil Stabilization

Soil stabilization is treating the subgrade material or subbase of a road so that it’s properties are improved. The improved properties are the ones we talked about in the previous section, ground improvement. The difference between soil stabilization and ground improvement is that soil stabilization deals with only improving characteristics of a subbase that will […]

Foundation strengthening and repair methods (Underpinning)

Underpinning methods do not treat the soil, but instead treat an existing foundation, either by modifying or repairing the foundation or by making additions or connections to a foundation. It is done in order to improve the foundation’s load carrying capacity, and transmitting foundation loads to an adequately strong soil layer. So, for existing structures, […]

Various ground improvement techniques

Without being too detailed, we will now list ground improvement and foundation improvement /repair techniques other than grouting and compaction below. Injection Systems: various aqueous solutions are injected into the ground, for treatment of collapsible and expansive soils, railroad subgrades, certain slopes. Rigid Inclusions: involves transferring of loads from weak to firm soil by using […]

Soil Compaction Methods

Compaction is reducing the soil volume, to make it denser and stronger and also less permeable. Compaction of soils can be done by heavy construction equipment, that use different methods to compact the soil. One method is to keep dropping a heavy weight from a certain height, over the entire intended foundation area. So to […]

Grouting Methods

There are different methods for grouting, and together they make up for a considerable part of ground improvement and/or existing foundation strengthening methods overall. A particle or chemical based grout usually with additives is injected into the soil with different placement techniques. The additives include lime, portland cement, fly ash, bitumen or their combinations. Grouting […]

Types of Piles

Now we will list the most frequently encountered types of piles. Note that almost all pile types we will mention below are made for resisting all of the first three of the loading types we just mentioned above, which were compression, tension and lateral from its top, but some of them can also be used […]

Pile Groups

Piles are often times combined into groups, by connecting them with pile caps at their top. When grouped, piles act differently than individually. This is called group action. The piles in groups must not be too close to each other, because each pile takes support from its surrounding soil. If the piles are too close, […]

Pile Capacity

Vertical downwards loads (Compression): Pile carrying capacity for vertical downward loads, comes from two things: The frictional resistance over their side face area and Their bottom tip resistance (end bearing resistance) foundations 2 So, piles generate friction force on their side face, plus develop strength at the tip. Tip resistance is also called “end bearing” […]

Deep Foundations (Pile Foundations)

Deep foundations, also called as pile foundations, are used when there is not sufficiently strong soil at a reasonable depth, and using shallow foundations would cause failure or excessive settlement of the structure, even if that same soil can be a sufficiently strong foundation material for a lighter project. For example, for a bridge, where […]