Special foundations: What are they and what are they for??

Puente Construccion Geoelements

Special foundations are used when the terrain does not meet the necessary conditions for a shallow foundation. (like footings or slabs) be safe or profitable. In other words: when the ground is difficult (as layers of low bearing capacity, presence of groundwater, high water tables or great geological variability) it is necessary to resort to more sophisticated technical solutions.

The objective is transmit the loads of the structure to strata of the ground that do have adequate resistance, or improve existing land to make it usable.

for us, It is essential to understand this definition, since our product portfolio (micropilotes, Anchors, corrugated vanes, micropile pipes) is oriented precisely to these specialized techniques.

When is it necessary to resort to special foundations?

Some common scenarios in which it is recommended to opt for special foundations are:

  • The surface soil has low bearing capacity and it is not possible to expand it efficiently with footings..
  • Presence of groundwater, collapsible terrain or very soft soils.
  • Construction in an urban area with small spaces or proximity to buildings that prevent traditional methods.
  • Need for lateral anchoring, retaining slopes or deep basement walls.
  • Large-scale works (infrastructure, bridges, tunnels) where the support depth is large.

In all these cases, the intervention of a company specializing in special foundations, and with technical support, becomes a requirement.

Main special foundation techniques

The most common techniques in the field of special foundations are described below.:

a) Drivers

These are deep foundation elements, usually concrete or steel, that transfer the load to the ground by tip or shaft (friction). Its use is common when the resistant layer is at significant depth..

b) Micropilotes

They are a variant of the piles, of reduced diameter and suitable for execution with light machinery or in small spaces. They offer great versatility for reinforcements, rehabilitation works or complicated urban areas.

c) Diaphragm walls and sheet piles

They are deep containment and support systems, widely used for basements, excavations or areas with high presence of water.

d) Anchors and post-tensioned anchors

They are used to stabilize slopes, walls, structures that need additional support, in combination with piloting, etc.

e) Land improvements

They include cement injection techniques, gravel columns, densification, etc., aimed at reinforcing the ground before installing a shallow foundation.

If you want to delve deeper into geotechnical foundations and regulations for special foundations, you can read this other article: “What is special foundation: Types and uses in construction published in CimentacionesEspecial.es.

4. Advantages of special foundations (and why they matter)

  • They allow construction where ordinary terrain would prevent it, expanding the range of work opportunities.
  • They increase structural security by guaranteeing support in competent strata.
  • They avoid settlement problems, cracking or structural failure that can arise from weak ground.
  • They can adapt to urban work limitations, reducing intrusion and environmental impact.
  • From a perspective 2025, The combined application of geotechnical techniques and digital modeling tools allows you to optimize costs, times and sustainability.

5. Good practices for choosing the right technique

When we face a project that requires special foundations, One of our priorities is to ensure that each technical decision is based on a rigorous analysis of the terrain and the real needs of the work.. It all starts with a complete geotechnical study, which allows us to know the composition of the soil, its bearing capacity, the presence of water and any condition that may influence structural safety. With this information, We evaluate the loads of the building or infrastructure and determine what solution (pilots, micropilotes, anchors or other deep techniques) fits the stage better.

Once the technique has been chosen, we give special importance to precise sizing of each element: the right length, the diameter, the necessary reinforcement and the type of execution that ensures optimal behavior on the ground. We know that good planning is directly reflected in the useful life and stability of the construction..

We also consider it essential to work with suppliers who offer certified materials and real technical support, since this guarantees not only the quality of the supply, but also the correct integration of each component in the work. In our experience, This close collaboration facilitates decision making and reduces unforeseen events during execution.

Besides, We integrate the chosen technique into the work as a whole: we analyze access, we manage possible vibrations or noises (especially in urban environments) and we coordinate the execution with the rest of the teams and installers to avoid interference. Finally, following the trends of 2025, we apply digital tools and artificial intelligence whenever possible. This allows us to optimize designs, foresee settlements, monitor the behavior of the terrain in real time and make more efficient and sustainable decisions.

Frequently asked questions (FAQ)

It is considered “special” when the conventional method (shoes, surface slabs) not viable due to poor ground conditions, presence of water, high loads or work limitations.

The pilot is a deep element of greater diameter and capacity; the micropile is smaller in diameter, lighter machinery, and suitable for interventions in complex spaces or rehabilitations.

Offer technical advice, supply of adapted materials (threaded bars, guilt, tubes, Anchors), certified quality and support on the job, which reduces risks and improves efficiency.

Techniques such as cement injection are used, gravel columns, soil densification, to reinforce the ground before supporting the special foundation.

Yeah. In 2025 focuses on optimizing design through digital models, real time monitoring, reduce construction impact and use efficient materials, which improves the sustainability of the project.