Some soldier piles and lagging walls are only meant to stand in place for a few months, but other walls in this category are intended for years (or decades) of use. If that’s the case for your wall, you’ll need to make sure it’s built to last.
Choosing precast lagging panels is a great starting point for a permanent retaining wall, but that alone won’t be enough. Here’s everything you need to know about establishing soldier piles and lagging walls that are ready to stand up to water damage, corrosion, and more.
Temporary vs. Permanent Soldier Pile and Lagging Walls
There are two basic types of soldier pile and lagging walls: temporary and permanent walls. Walls in the first group aren’t designed to last any longer than a few years. Because of that, you may be able to get away with using timber lagging panels in these structures.
Permanent soldier pile walls need to meet a different (and higher) set of standards. Since these walls must stand for decades, they should incorporate materials you can rely on for an extended period of time. That means timber panels aren’t suitable for these walls – even treated timber doesn’t last as long as other construction materials.
Instead, you’ll be much better off choosing precast lagging panels for your permanent soldier pile and lagging wall. The National Precast Concrete Association has stated that precast concrete products usually last for 50-100 years, making them an excellent choice for applications like these.
What Determines Soldier Piles and Lagging Walls’ Durability?
While the construction material you use in your soldier pile and lagging wall can help you estimate its lifespan, that’s not the only thing you’ll need to think about. Other things that will determine the durability of your wall include:
- Freeze/thaw cycles. When water gets into concrete lagging panels, it expands as it freezes and contracts as it melts. Eventually, that process will weaken these materials.
- Chlorides. If chlorides penetrate concrete surfaces, they can jump-start the corrosion process – putting your panels’ steel reinforcements at risk.
- Groundwater. Uncontrolled hydrostatic pressure has a serious impact on the concrete panels used in retaining walls. Without enough drainage, this pressure can build up and damage (or even destroy) these walls.
- Soil composition. The stability and chemical composition of your soil will affect your retaining wall’s performance, as well.
Maximizing Your Wall’s Service Life With the Right Concrete Mix
Another factor that will have an impact on the soldier piles’ and lagging wall’s service life is the concrete mix you choose for your lagging panels. Some types of concrete are more durable than others, and even if a concrete mix is suitable for lightweight use, it may not be a good choice for a retaining wall. Lagging panels made from these mixes will crack sooner than you might expect, forcing you to repair or replace your wall ahead of schedule.
The good news is that you won’t have to choose a concrete mix on your own. Ideally, the company you choose to supply precast lagging panels will get involved by performing a detailed assessment of your site. During this visit, they’ll assess your situation and take steps to ensure your lagging panels consist of the right type of concrete for your needs.
Controlling Cracks in Concrete Panels
In order to withstand constant pressure from the earth with minimal cracking, your lagging panels need to meet highly specific tolerances. Since precast lagging panels are manufactured in controlled environments, they’re a much better choice than cast-in-place concrete panels when this is a concern.
That said, some degree of concrete cracking is inevitable – especially on the corners and edges of concrete surfaces. Control joints can help by influencing where cracks occur in your concrete panels. These intentional weak spots encourage concrete to crack in a straight line, reducing your risk of random (and more harmful) cracks.
The Importance of a Draining and Waterproofing Strategy
No matter how much thought you put into other aspects of your retaining wall, it won’t function like it should if you don’t pay attention to drainage. To give this wall the high-quality drainage it needs, you can add:
- Weep holes. These holes help the water that builds up behind retaining walls escape.
- Chimney drains. A chimney drain is a vertical column of free-draining material that directs water away from certain areas.
- Geocomposite drains. These advanced, multi-layered drain products allow for faster water flow than “standard” gravel drains.
- Outlet protection. Uncontrolled water flow from drains can contribute to erosion, but outlet protection will reduce this flow and protect the nearby ground.
Meanwhile, waterproofing your wall can protect it from the effects of water intrusion (which will cause it to crack and deteriorate over time). You can waterproof your soldier pile wall with:
- Integral waterproofing. This involves adding a waterproofing agent to the concrete mix used in your wall’s lagging panels.
- Cementitious waterproofing. By applying a cement-based mixture to your retaining wall, you can give it extra protection from water.
- Sheet membrane waterproofing. Applying pre-formed sheets designed to resist water to your wall is another effective way to waterproof it.
- Liquid membrane waterproofing. This is a liquid coating applied to retaining wall surfaces to help mitigate the effects of water.
Protecting Your Wall From Corrosion
Along with water damage, you’ll need to look out for corrosion on the metal used in your retaining wall panels. Steel rebar, other embeds, connections, and exposed hardware are all susceptible to corrosion.
Cathodic protection can help you avoid this problem: this electrochemical process reduces a metal surface’s electric potential and slows corrosion. To benefit from cathodic protection, try coating metals with another metal that corrodes more easily (sacrificial anode cathodic protection) or polarizing these surfaces with an external electrical current (impressed current cathodic protection).
What Should Your Wall’s Maintenance Plan Include?
Creating and following a maintenance plan is an excellent way to extend the lifespan of a soldier pile and lagging wall. While putting together this strategy, make a point of thinking about:
Access Points in the Soil
In solider pile and lagging walls, precast lagging panels bridge the gaps between steel beams. When one of these panels reaches the end of its service life, you’ll need to know how to remove it from the beams holding it in place. Including panel access in your maintenance plan will make this process easier than it would be otherwise.
Inspection Intervals for the Ground Retention
If your retaining wall has developed a problem, you’ll want to know about it before it has a chance to get worse. What this means for you is that you’ll need to schedule regular inspections of your wall.
A well-constructed permanent retaining wall can last for decades, but you shouldn’t wait anywhere near that long to check the condition of your structure. It’s best to closely inspect retaining walls once every year or two. By doing that, you can make sure your wall is stable, crack-free, and not showing any other signs of wear and tear.
Replacement Strategies and the Limits of Your Area
No matter how well-designed your permanent soldier pile and lagging wall is, and no matter how much work you put into inspecting it, it won’t last forever. Having a strategy for replacing this wall and its components can help.
Sometimes, making improvements to your soldier pile and lagging wall can give it a new lease on life. To that end, you can add better drainage to your retaining wall, reinforce this structure so it can handle unexpected loads, and replace aging lagging panels with new panels.
On the other hand, there will always be situations where you’ll need to tear down your wall and build an entirely new wall to replace it. This is especially true when it comes to failing walls that were built by unqualified contractors. In that situation, it’s better to start from scratch while working with a company that’s worthy of your trust.
Getting Acceptance for Soldier Pile and Lagging Walls
Before you can break ground on a soldier pile and lagging project, you’ll almost certainly need to get approval from your local governing authority. Creating a submittal package for your project is a crucial part of this process. These packages should provide:
- Details on what you plan to build
- Shop drawings
- Relevant structural calculations
- Information on drainage and bearing
- Other relevant details
While going through these packages, reviewers look for problems like missing drainage plans, a lack of details on corrosion protection, and incomplete lifting and handling engineering. If they don’t find any issues along these lines, you should be able to continue moving forward with your project.
Don’t Settle for Less From Your Precast Lagging Panels
If you want to build a permanent soldier pile and lagging wall, you’ll need to find precast lagging panels you can count on. At American Precast Concrete Inc., we take pride in providing high-quality materials like these for residential and commercial construction projects alike. Take the first step by reaching out to us today!