Istasazeh
FA Ar

Home - Istasazeh services - Earth retention - What is Berlin Wall or Soldier Pile wall and Lagging wall System ?

One of the methods of the earth retention the Soldier Pile wall and Lagging wall system (berlin wall).

Soldier Pile wall and Lagging wall System is actually a combination of:

  • Soldier pile (concrete or steel piles): width double IPE, pipe, in situ concrete pile, and
  • Lag such as: shotcrete or precast concrete, timber or steel sheet.
Soldier Pile wall and Lagging wallsystem
Berlin wall – Istasazeh Co

For trapping steel and concrete piles, about 25% of their length is considered as the root of the pile. In order to prevent local falls between the piles, in-situ or precast concrete surfaces, timber, etc. are used.

One of the common concrete surfaces in urban projects is concrete shotcrete which after excavation, a steel bar mesh is placed between the piles and then by shotcrete, a concrete surface is created between piles.

Precast concrete can be used for permanent stabilization and timber can be used for temporary stabilization.

To earth retention or prevent settlement in the vicinity of settlement-sensitive structures, the combination of Berlin wall method with  nailing, anchorage or struts is also used.

Execution of Soldier Pile wall and Lagging wall system (Berlin Wall) alone or in combination with other stabilization methods such as soil anchorage and struts
Execution of Berlin wall system (Berlin Wall) alone or in combination with other stabilization methods such as soil anchorage and struts

Use of timber in the Soldier Pile wall and Lagging wall system (Berlin Wall) system to prevent local falls
Use of timber in the Soldier Pile wall and Lagging wall system (Berlin Wall) system to prevent local falls

History Soldier Pile wall and Lagging wall system (Berlin Wall)  

The Soldier Pile wall and Lagging wall system (Berlin Wall) is one of the oldest methods of the earth retention. It has been successfully performed in major cities such as New York, Berlin and London since the 18th century. The reason for naming this method the Berlin Wall goes back to its use in the 1930s on the Berlin Underground train. The Soldier Pile Wall is often used interchangeably with the Berlin Wall.

Execution of Berlin wall method
Execution of the Soldier Pile wall and Lagging wall system (Berlin Wall) in the trenches along the highways and roads

Basic Design of soldier pile wall and lagging wall system

Specifications of 1 meter of concrete surface section plus specifications of pile materials divided by their distance are given to 2D Geo-Slope software and Plaxis 2D finite elements, and then the reliability coefficient and wall displacement are obtained. In 3D software such as Plaxis 3D, the whole wall is simulated and only the specifications of the materials are given.

Execution method of a of berlin wall method

  1. The Execution of piles:

In the case of using concrete piles, in situ concrete piles should be executed according to the executive plans. If metal piles are used, which are often wide double IPE, IPE or pipes, the piles are drilled first and then the roots of the piles are concreted.

Steel piles are then placed in the drilled locations. Of course, steel piles can also be made by compacting. The type of pile and the diameter of the pile depend on the load adjacent to the excavation and the soil characteristics.

2) Completing the wall between the piles:

 After the execution of the piles, excavation begins and is excavated to the appropriate level for the execution of steel mesh or timber, and then to prevent local fall of the steel mesh and then shotcrete is done or timber is placed.

This process continues to the end of the excavation. In cases where the displacement near the excavation is relatively sensitive, the back of the timber should be filled with dense material. The thickness of timber or concrete surface depends on the type of soil, the distance of the piles, etc.

The forces are transmitted to the concrete or steel piles (Soldier Piles) by concrete or timber and then they are tolerated by concrete or steel piles in the form of a cantilever and cause an excavation static. If concrete or steel piles alone are not able to withstand these forces, use a combination of this method with other stabilization methods such as nailing, anchorage, struts and pressure on the piles are tolerated.

For structures designed in the final limit state (LRFD), the service life of timber is about 75 years. Therefore, timber is not acceptable for structures that have a service life of more than 75 years.

The following American highway regulations are used to design timber:

“Lateral Support Systems and Underpinning” (Report No. FHWA-RD-75-130)

According to this regulation, for 3 different soil types, the conditions of timber are presented:

Timber conditions for 3 different types of soils provided by FHWA
Timber conditions for 3 different types of soils provided by FHWA

Combining the Berlin wall method and soil anchorage method
Combining the Berlin wall method and soil anchorage method

Combining the soldier pile wall and lagging wall system  and struts
earth retention using the soldier pile wall and lagging wall system, including piles (Soldier pile) and timber
Combining the Berlin wall method and struts
Combining the soldier pile wall and lagging wall system and struts

Applications of berlin wall method

  • Suitable for excavations where the water level is below the floor level of the excavation
  • Suitable for excavations around which there are no settlement-sensitive structures
Berlin wall method
Applications of soldier pile wall and lagging wall system (Berlin Wall)

Advantages of Applications of soldier pile wall and lagging wall system (Berlin Wall)

The following are some of the advantages of the Berlin wall and lagging wall system.

over other methods of stabilizing the excavation:

  • Suitable price compared to other methods of stabilization
  • Easy and fast execution
  • No need for special equipment
Advantages of the soldier pile wall and lagging wall system (Berlin Wall)
Advantages of the soldier pile wall and lagging wall system (Berlin Wall)

The following are some of the disadvantages of berlin wall compared to other methods of stabilizing the excavation:

  • No recommendation for permanent stabilization
  • No recommendation for high water level
  • Low stiffness compared to stabilized walls in other ways
Disadvantages of the soldier pile wall and lagging wall system (Berlin Wall)
Disadvantages of the soldier pile wall and lagging wall system (Berlin Wall)

Related contents:

Federal Highway Administration (FHWA)
Aarsleff , Berliner walls
Deep Excavation , SOLDIER PILE WALLS
Bauer-Egypt , Berlin Walls
Finesoftware , Soldier Pile Wall
Federal Highway Administration (FHWA)

Leave a Reply

Your email address will not be published. Required fields are marked *

All Articls

What is Truss Retaining Structure?

Truss retaining structure is one of the common excavation methods [...]


Read More

What is a diaphragm wall or slurry wall?

Diaphragm wall or slurry wall is one of the methods [...]


Read More

What is soil anchorage? (Ground anchors and anchored systems)

Ground anchors and anchored systems or soil anchorage method, like [...]


Read More

What is top down construction method ?

Top down construction method is a relatively new method of [...]


Read More