Retaining walls serve multiple purposes on construction sites, but they are primarily used to make sloped areas more functional and aesthetically pleasing. Building these walls can help you overcome the unique challenges that hillside and sloped-site development presents, maximising your use and enjoyment of the property.
Many factors influence the design and construction of retaining walls. Failing to consider these factors before project commencement will increase the risk of wall distress and failure, jeopardising your investment and entire financial well-being.
Here's a look at some common problems with retaining walls and how to avoid them.
Incorrect wall design
Not all retaining walls are created equal. Many design options for walls exist to match project-specific performance, safety and decorative requirements. Some common types of retaining wall designs include:
- Reinforced retaining walls
- Gravity retaining walls
- Gabion retaining walls
- Anchored earth retaining walls
- Crib retaining walls
- Sheet piling walls
- Cantilevered retaining walls
- Green retaining walls
Each wall type has specific features, benefits and drawbacks that affect its suitability for use in particular applications. Building the wrong wall system on your sloped-site property will make problems inevitable.
The best way to avoid wall failure due to design issues is to understand the applications of different wall systems.
Failure to incorporate an effective drainage system into the design of your retaining walls may lead to saturation of the soil behind the walls. The walls will eventually collapse due to the increased lateral pressure.
Retaining walls require good drainage to allow stormwater to move smoothly through your landscape. Gravel backfill (or similar aggregate) should be installed directly behind the walls to facilitate proper drainage. Compacted native soil goes behind the granular backfill.
Also, drain pipes installed at the bottom of the walls can help prevent saturation of the native soil and direct water away from the foundation of the walls.
Calculating the maximum loads your retaining walls will bear is essential for building strong, durable walls. Once you know the load requirements for the walls, you need to use building materials that can match those requirements.
For example, steel rebar can provide the additional strength that concrete wall systems require for high-strength applications.
Retaining walls require a strong and stable foundation to withstand the loads due to lateral, hydrostatic and other pressures. If the foundations of these walls are weak and unstable, the walls will inevitably fail.
Proper site preparation, adequate foundation depth and soil compaction are essential for reducing this risk.
Retaining wall construction is a job that requires sufficient knowledge and experience in hillside site development to do correctly. Contact a retaining wall contractor to get your quote and take the guesswork out of the project.