- Retaining wall home
- Four common types of concrete retaining walls
- How to Design Concrete Retaining Walls
- General retaining wall design
- Building codes for retaining walls
- How to determine lateral earth pressure
- Determining concrete retaining wall proportions
- Provisions for joints in concrete walls
- Backfill drainage of retaining walls
- The importance of groundwork and compaction
- How to Install Concrete Retaining Walls
- Retaining Wall Cost
- Decorative Face Options for Retaining Walls
- Decorative poured walls: Reproduce the look of stone or masonry
- Vertical concrete overlays
- Form liners for cast-in-place vertical concrete
- Related Information:
- Landscape Retaining Walls: Information and design ideas for residential retaining walls from LandscapingNetwork.com
- Board Formed Concrete
General Retaining Wall Design
Retaining wall design and wall type selection is driven by several factors.
These factors include:
- Required wall height
- Ease and speed of construction
- Ground water conditions and soil characteristics.
Other factors can include skilled labor and material availability, building codes, site accessibility, aesthetics, local building practice, etc. Ultimately, all retaining walls serve to hold back a vertical or near vertical face of soil that would, without adequate retention, cave, slump or slide to a more natural slope.
In most states, retaining wall designs taller than about four feet must be designed by or approved by a qualified, licensed professional engineer. Additionally, it is important to check with and adhere to local building codes prior to any construction, even when walls are shorter than four feet. Retaining walls are, and should always be viewed as load bearing members first, and aesthetic groundscapes second.
Designing any retaining wall requires a knowledge of lateral earth pressure.
Once the lateral earth pressures are known, the wall is checked for stability. This includes checks for wall overturning, base sliding, and soil bearing capacity failures. After the wall is sized, each wall member is checked for adequate strength and steel reinforcing is determined.
One of the most common and telling failures of retaining walls is the inevitable tilting, cracking and bowing of brick, timber and concrete block retaining walls built by homeowners, well meaning builders, and landscapers. These "problems" truly are failures, since the wall has not performed the task it was built to do, and that is to hold back the soil.
The failures also clearly demonstrate the lack of knowledge or design that is required by a successful retaining wall design. By understanding how a wall works, and how it can fail, it is possible to engineer a retaining structure that will meet all foreseen environmental, structural and construction demands.