There are many different types of retaining walls, but soldier pile and lagging walls are a popular option thanks to their affordability and ease of construction. This type of wall relies on soldier piles, or steel beams installed at regular intervals.
In these structures, lagging panels are responsible for connecting soldier piles and transferring lateral loads to these beams. If you aren’t sure how to put your panels in place, this step-by-step field guide to precast lagging panel installation can help.
Choosing a Material for Lagging Panels
Once you’ve decided to build a soldier pile and lagging wall, your next choice will be to pick a material for the lagging panels in this structure. Both timber and precast concrete are common choices for retaining walls, but the latter option delivers better results than the former.
One of the biggest benefits that comes with choosing precast concrete over timber is concrete’s longevity. Though treated timber lagging panels can stay in place for decades, the National Precast Concrete Association states precast concrete typically lasts for 50-100 years.
Precast concrete lagging panels also excel in terms of:
- Quality control. Unlike timber panels, precast panels are manufactured in controlled environments to meet precise tolerances.
- Precast Installation speed. Since precast lagging panels meet exacting specifications, workers can install them as quickly as possible.
- Moisture resistance. Precast concrete manufacturers design their products with watertightness in mind.
- Overall value. When you go with precast concrete lagging panels, you’ll save money by avoiding delays and rework.
The Process of Installing Precast Lagging Panels
Soldier pile and lagging walls are relatively easy to build, but you’ll need to follow the right sequence of steps while creating one of these structures. As part of that, you should:
1. Review Engineering Plans
If you take a close look at engineering plans for your project before you order lagging panels, you can be confident in the knowledge that these panels will meet your needs. While you go through these plans, consider your:
- Pile spacing. The exact span your panels will need to cover depends on the distance between each soldier pile in your retaining wall.
- Pile type. Not all soldier piles are the same, and your lagging panels should take that into account. Some soldier pile varieties commonly used in retaining walls include wide flange beams and H-piles (a subtype of wide flange beams that are equally wide and deep).
- Panel thickness. Your retaining wall’s unique circumstances will determine the right thickness for your lagging panels. Take some time to think about where you’re installing your wall and what the best panel thickness might be for your situation.
- Embedment depth. To find your ideal embedment depth, review factors like your site’s soil conditions and groundwater levels.
- Installation tolerances. While retaining walls are somewhat flexible by design, they still need to have clearly defined tolerances. Make sure your construction plan covers tolerances for pile spacing variability, panel bearing, and backfill contact.
2. Prepare Your Site for Panel Installation
After you check engineering plans for your retaining wall, you’ll be ready to buy lagging panels for your project. Before they arrive, make sure you’ve correctly installed and aligned your soldier piles so precast installation can go off without a hitch. It’s also wise to make sure your construction crew has full access to any equipment and storage areas they’ll need for lagging panel installation.
3. Inspect Your Panels
When you opt for precast concrete instead of cast-in-place concrete, you won’t have to take care of lagging panel construction on your construction site. But once your panel supplier makes a delivery, it’s in your best interest to double-check these components before installing them in your wall.
At this point, take a look at your panels’ and review:
- Dimensions. If you chose a trustworthy company for your precast concrete lagging panels, you shouldn’t have to worry about getting panels that don’t meet your specifications. Still, it’s not a bad idea to make sure your panels meet your tolerances.
- Edges. Issues like spalling commonly start at concrete panels’ edges. Because of that, you should make sure your panels aren’t already dealing with problems like these.
- Lifting insert integrity. Lifting points are a crucial part of any lagging panel, since these inserts allow construction workers to lift panels with heavy equipment. Before they get started, ensure your panels’ lifting points are fully intact.
4. Excavate in Lifts
Once your inspections are complete, it’s finally time to start lagging panel installation work. First, your crew will need to take care of excavation. To do that, they’ll need to remove soil in controlled sections designed to match the height of your lagging panels.
5. Place Panels
With excavation work taken care of, your team will be ready to put lagging panels into place. This process involves lifting panels with approved rigging and sliding them between your soldier piles’ flanges.
6. Ensure Panels Are Supported
As soon as your panels are in place, check them to ensure they’re evenly supported and aligned in your wall’s pile system. While doing this inspection, make sure your panels are level, as well.
7. Backfill and Compact
Backfilling your retaining wall can help you avoid settlement and other problems later on. When your crew has installed your panels, place approved backfill behind them and compact the backfill in controlled lifts.
8. Repeat as Necessary for Each Precast Panel
At this point, all your team has to do is continue excavating, placing panels, and backfilling. Once you reach your final excavation depth, your lagging panel installation efforts will be complete.
Know Where to Order Your Lagging Panels for Precast Installation
No matter how closely you follow the steps listed above, the success or failure of your retaining wall will ultimately depend on the quality of your lagging panels. When they choose American Precast Concrete Inc. for these components, contractors get exceptional made-to-order lagging panels that meet their exact specifications.
Are you getting ready to place an order for lagging panels? If so, contact us today – we’ll give you a spec sheet and typical details package.