Most Common Retaining Wall Failures and How To Fix Them
Retaining walls are essential in modern construction because they prevent soil erosion and landslides in mountainous or sloping terrain. These structures are common in residential, commercial, and infrastructural projects. They may improve a property’s visual appeal while protecting it from natural forces. However, retaining walls, like any other man-made structure, are prone to failure for various causes, which can be costly and dangerous.
As experienced excavators and retaining wall builders, we have witnessed several retaining wall failures. We become familiar with their origins and effects.
Read further as we will help you avoid them or somehow give you idea on how to fix them. You will discover helpful tips that can assist you in designing, constructing, and maintaining a solid and lasting retaining wall that matches your demands, whether you are a homeowner, contractor, or engineer.
Dig in!
Table of Contents
Early Signs of Retaining Wall Failure
Retaining walls are structures made to keep back soil or other materials. They are essential in halting landslides and erosion. To avoid potential dangers or property damage, it’s crucial to know the indicators of retaining wall failure, as they can fail just like any other construction.
Leaning or Bulging Walls
Any observable bending or bulging in retaining walls—which should be perpendicular to the ground—indicates a probable failure. The wall may be sagging or folding outward, leading to a buildup of dirt and water pressure behind it. If this pressure is not relieved, the wall may collapse.
No Water Coming From The Weep Holes After Rain
For adequate retaining wall drainage, weep holes offer a tiny aperture. After a storm, the absence of water flowing through weep holes is a particularly alarming symptom since it signals inadequate drainage conditions. This can result from clogged weep holes, a scarcity of draining aggregate, or improperly graded dirt away from the wall.
Subsidence in the Surrounding Area
Soil subsidence (sudden sinking) in the vicinity may indicate that the force acting on your retaining wall is shifting. Before a wall is built, precise calculations are required to determine the pressures pushing against it; thus, alterations might lead to ultimate failure.
Fractures or Cracks
The wall’s surface may crack or fracture for several causes, including water damage, soil movement, or poor building materials. The wall may begin to crumble when the cracks become more significant over time from modest beginnings.
Water Damage
Retaining walls are significantly threatened by water. If water is not removed from the area around the wall, the soil behind it may get saturated, putting pressure on the wall. Signs of water damage include stains, fractures, and mould development on the wall’s surface. This pressure has the potential to cause the wall to collapse.
Most Common Types of Retaining Walls Failure
Understanding each form of retaining wall failure is crucial to pinpointing the root cause and choosing the most effective line of action to address the issue. The four most typical kinds of retaining wall collapse are as follows:
Sliding
A form of failure known as overturning happens when the base of the retaining wall rotates. This can take place when the wall is improperly secured or when excessive soil pressure behind the wall causes it to lean forward. There may be a perceptible lean or bulge in the wall due to overturning.
Bearing Capacity Failure
The bearing capacity failure occurs when the retaining wall’s foundation cannot hold the weight of the soil behind it. The wall could sink or crumble as a result of this. Cracks or fractures and soil movement along the wall indicate bearing capacity failure. Due to rotation in the base brought on by the lateral earth pressure, the pressure beneath the base of the wall could be more consistent.
Retaining wall failures might result from an increase in the soil pressure over the permitted bearing pressure. As a result, it is crucial to regularly evaluate the soil pressure beneath the base of retaining walls.
Excessively Deflection
Excessive deflection happens when the retaining wall bends more than intended, usually due to weak building materials or methods. Visible bending or drooping in the wall and surface cracks or fractures are indicators of severe deflection.
Why Do Retaining Walls Fail?
Understanding the underlying causes of retaining wall failures is essential to preventing further incidents. The following are typical causes of retaining wall failure:
Inadequate design or construction
Poor construction or design is a significant factor contributing to retaining wall collapse. Retaining walls constructed improperly, with defective materials, or without the appropriate reinforcements are prone to failure. Failures can also result from design flaws, including inaccurate load estimates, the wrong wall height, or inadequate anchoring.
Faulty drainage
Soil saturation is one of the most prevalent reasons for retaining wall problems. When soil or backfill is allowed to get saturated with water, pressure is significantly raised. Wet soil is heavier than dry soil and may become stressed if the retaining wall is not built to support the added weight.
Adequate drainage should be built to guide the water out and away from the structure to prevent saturated soils. A portion of the water pressure can be decreased by regrading the area to deflect water flow from the wall. Landscapers can drill additional weep holes for improved surface drainage. Materials like crushed and pea gravel can offer adequate drainage to prevent saturated backfill.
Conditions and soil composition
Essential elements that might contribute to a retaining wall’s collapse include the soil’s composition and conditions. The wall may sink, slide, or shift in excessively soft, sandy, or unstable soil. Additionally, the severe strain on the wall from soil movements like settlement, erosion, or expansion might cause it to fail.
How To Fix Retaining Walls Failure
Is there any damage or failure to your retaining wall? Don’t put off fixing it until it’s too late! Follow these easy procedures to repair your retaining wall and stop additional damage. Your retaining wall may be made solid and stable once more with an excavator and simple equipment.
Assess the damage
To ascertain the degree of the damage, examine the retaining wall. Keep an eye out for bulging, tilting, or breaking. The wall might need to be replaced if the damage is extensive.
Strengthen the wall
You can strengthen the wall if the damage is minimal. Rebars, or steel reinforcing bars, can be inserted into the wall to reinforce it. Concrete can also be used to close up any gaps or fissures.
Plan the fix
You will need to design the repair procedure based on the severity of the damage. This can include strengthening the current structure or removing and replacing damaged wall parts.
Gather resources and tools
Depending on the repair you’re performing, a level of concrete, rebar, mortar, and other supplies will be needed.
Manage drainage
A retaining wall might collapse due to poor drainage. If you see the water rushing over the wall or gathering behind it, the drainage may need to be improved. This may entail placing drainage pipes or gravel behind the wall to deflect water away from the wall.
Rebuild or replace the wall.
You might need to replace or rebuild the wall if the damage is too severe to be repaired. This could include knocking down the existing wall and erecting a new one. To guarantee the new wall is solid and long-lasting, utilize excellent materials and adhere to suitable building methods.
Pro tip: We always advise everyone to remember that repairing a retaining wall may be complicated and challenging. Hence, it’s frequently better to seek a qualified contractor’s advice to ensure the work is completed correctly and safely.
Frequently Asked Questions
Retaining walls are generally seen as independent structures; therefore, under the right circumstances, damage to them may be covered by your home’s insurance. Coverage may be available when harm is brought on by a “covered loss” (also known as an insured event), such as lightning, wind, fire, or a car crashing into a wall.
Large, apparent fissures indicate that your retaining wall needs to be rebuilt. A warning indicator that your wall can fall is when a section separates from the main construction. Depending on the damage, it would help if you either fixed it or replaced it. Water leaks are an indicator of drainage issues.
If the existing retaining wall cannot be repaired, you should construct a new one. You should only remove a retaining wall with another slope stabilization strategy unless you are attempting to level a surface.
The strain that the retaining wall must withstand might more than quadruple if water pools or the soil becomes saturated due to inadequate drainage. Although significant safety considerations are built into the requirements for retaining wall design, the wall may ultimately crumble without adequate drainage.
Final Thoughts
Repairing a deteriorating retaining wall might seem overwhelming, but it doesn’t have to be. You may restore your retaining wall to good condition and guarantee the security and appeal of your home by adhering to a few simple rules.
Keep in mind that a well-constructed and maintained retaining wall may increase your property’s value, safety, and beauty. Still, one that is deteriorating can result in severe issues and costs. Therefore, don’t hesitate to take action and safeguard your investment and peace of mind if you see any indications of retaining wall collapse. Working with skilled experts who can assist you with retaining wall repairs and make sure everything is done safely and successfully is still the best decision in having your retaining wall fixed.
