Photo: DDES
A retaining wall holds back the push of the soil and water. Its design needs the soil study and follows Chapter H.6 of the NSR-10, which covers retaining structures. DDES designs cantilever, gravity and basement walls and supervises their construction.
- Code
- NSR-10, Chapter H.6
- Service
- Structural design
- Needs
- Geotechnical study
What to have at hand
- Height of the level change and length of the wall.
- The soil study or, if there is none, authorization to carry one out.
- What is behind and above it: road, neighboring building, parking.
- Photos of the site and of the existing drainage.
How we solve it
- Reading of the soil study: soil parameters and water level.
- Calculation of earth pressures, including surcharges and earthquake.
- Design of the wall and its drainage, and checks for overturning, sliding and bearing capacity.
- Drawings, calculations and support during the excavation.
Why do retaining walls fail?
The most common failures come from water: a wall without drainage takes water pressure on top of soil pressure. Walls designed without a soil study, or with loads on top nobody accounted for, also fail.
What does the NSR-10 require?
Chapter H.6 covers retaining structures, and Title H as a whole requires the design to rest on a geotechnical characterization of the site. During excavation, the construction sequence must also be designed (H.8.1).
Related projects
Technical notes
Geotechnical study: how many borings, and how deep, the NSR-10 requires
The building's category sets the minimum number of borings and their depth. Title H sets it out.
Soil profile in the NSR-10: types A to F and how they change the design earthquake
In the same city, the same building may have to be designed for an acceleration three times higher depending on the soil. Table A.2.4-1, explained.
Expansive clays in southwest Barranquilla
Foundations for soils that swell in the rainy season and shrink in the dry season.
Frequently asked questions
Does every retaining wall need a soil study?
Yes. The pressure depends on the soil and the water, and without that data the design is a guess.
Can a block wall retain soil?
Only for very small heights and with a design. Unreinforced masonry walls are not made to resist lateral earth pressure.
Has DDES designed basement walls?
Yes. The Ébano and Casa Grande buildings included basement and semi-basement retaining walls.
Other situations
- Adding a second floorBefore adding a floor you need to know whether the house can carry it.
- Home structural retrofitSo an older structure resists what today's code requires.
- Crack assessmentNot every crack is serious, but every crack that grows needs to be studied.
- Warehouse designFrames, roof, floor slab and foundation, designed together.
- Tanks and poolsStructures that must not only stand but also not leak.
- Steel mezzanineMore usable floor area inside the same warehouse or store.
- Building permitWhich structural documents the curaduría asks for and who signs them.
Last updated:
Contact
Need a retaining wall?
Tell us the height, the lot and whether you have a soil study. A DDES engineer replies.
Our team works in Spanish. You can write to us in English and we will get back to you.
Photo: Julia Taubitz / Unsplash