12 Things You Didn't Know About Combi-Wall Systems

Combi-Walls, also known as combined sheet piles, are a combination of sheet pile walls and steel pipe piles (king piles). Combi-walls are great for marine applications where extra support and stiffness are needed. They’re particularly ideal for dam projects, flood-proofing projects, canal construction, and port construction. Here are twelve things you may not know about combi-walls:

1. Their unique construction gives them extra strength and stiffness. In order to install combi-walls, you need to drive the king piles, usually steel tubular piles, into soil. It’s necessary to use a pile driving frame to make sure the piles are properly and securely installed. Oftentimes, once king piles are done being driven, they are backfilled with reinforcing steel and concrete. Then, locks are welded to those piles to install sheet piles. The last step in combi-wall construction involves placing the sheet piles in between the king piles. This is usually done using a vibratory hammer. It’s also common for combi-walls to be stabilized using anchors or horizontal struts.

2.They work in all types of soil. This is one of their key advantages in comparison to other options. No matter what the soil conditions, combi-walls can get the job done. This is also why they’re particularly well-suited for marine applications.

3. King piles aren’t always tubular. Although tubular is the most common type of king pile, box, bearing piles, and other types of fabricated piles are also used in certain applications of combi-walls.

4. H-piles are also sometimes used in the construction of combi-walls. H-piles are occasionally combined with sheet piles to form combi-walls for particular uses.

5. For marine jobs, king piles need to be driven deeper. This allows for greater axial capacity and ultimately more stiffness and load bearing capacity.

6. King piles must be driven straight and vertically. If they’re not precisely parallel to each other, the combi-walls will be compromised and may not provide an adequate amount of stiffness and support.

7. Sometimes ground pre-treatment is necessary before pile driving begins. This may be required when driving conditions are difficult. Jetting or excavating within the king piles can be helpful.

8. They’re an attractive alternative to structures used for similar purposes. They’re less expensive than secant walls and offer a lot more load bearing capacity in comparison to sheet pile walls. Secant walls also have issues like low verticality tolerance in deep piles, and it’s difficult to waterproof their joints. Combi-walls don’t have these same issues, making them an appealing alternative in addition to their lower price-tag.

9. They can be used for both permanent and temporary applications. They’re durable enough for the long-haul but also fairly simple to dissemble and re-use on other job sites. Moreover, even if combi-walls are meant to be permanent, they can easily be removed should the needs of a site change.

10. Permanent combi-walls should be protected against corrosion. Although durable, they are susceptible to eventual corrosion, particularly in marine settings. Care should be taken to provide them with protective coating to slow down corrosion and prevent rust, particularly in wet areas.

11. They are a bit pricier than standard sheet piles. But for jobs that require greater wall stiffness, more wall moment resistance, and greater load bearing capabilities, they’re worth the extra cost for the extra support.

12. Their individual parts can be sold or re-used for different purposes. Once temporary combi-walls are deconstructed, their king piles and sheet piles can be sold or re-used for different projects. They don’t necessarily need to be used to construct future combi walls. This makes combi-wall parts even more versatile in the long-term.

BUY AND SELL USED COMBI-WALL AND SHEET PILE WITH EIFFEL TRADING

Eiffel Trading currently has several options for used combined wall systems (including PZ/PZC sheet pile, AZ/NZ/ZZ/Hoesch sheet pile, and cold-rolled sheet pile), and used H-pile for sale. Don’t see what you need? Create a wanted listing for free today.

Learn more about selling with Eiffel Trading to get started selling your used sheet pile and other materials today.

If you would like more information or further assistance, call us at 1-800-541-7998 or email sales@eiffeltrading.com.