Despite their seemingly robust and enduring structure, retaining walls can fail. Most times, these failures aren’t a sudden occurrence; instead, it’s a gradual process due to several factors. So, in this article, we’ll explore why retaining walls fail.
Poorly Constructed Subgrade or Footing
Like any other structure, retaining walls require a solid foundation or footing. When a retaining wall is built on a poor subgrade—shifting gravel or inappropriately compacted soil, it’s like playing a risky game of Jenga. Over time, the structure is doomed to fail.
Retaining Walls Fail – Improper Drainage
Next, inadequate or faulty drainage systems can expedite the failure of retaining walls. When water collects behind the wall with no means of escape, it puts significant pressure on the structure, causing it to wear down over time or even collapse. Consequently, a well-maintained drainage system is crucial for the longevity of retaining walls.
Incorrect Backfill Procedures
Retaining walls use backfill. Backfill is the soil banked against them to help manage groundwater and ensure stability. However, if the backfill isn’t layered correctly to allow easy water drainage, your wall can suffer damage similar to that caused by improper drainage.
Retaining Walls Fail Because of Incorrect Building Materials
The kind of material used in building a retaining wall is crucial to its durability. If the stones used for construction are soft, they might crumble under strain. Similarly, using top-row rocks for the base or vice versa can undermine the wall’s structural integrity.
Building Extra Structures on Top of the Retaining Wall
Retaining walls aren’t designed to support additional structures. So, if you try to build on top of a wall that wasn’t designed to bear such weight, it’s an invitation to failure. Walls built to support an extra load, such as a deck, must be specially reinforced to handle the added pressure.
Construction Errors or Poor Design
Errors and miscalculations made during construction, such as faulty information or poor construction methods, are reasons why retaining walls fail. These errors can lead to inadequate depth or weight distribution, which weakens the final structure.
Retaining Walls Fail Due to Age
Lastly, like any other structure, retaining walls are not immune to the ravages of time. Factors like the constant weight of the backfill, ground shifting, stone cracks, or the drainage system’s erosion can all contribute to an aged wall’s failure.