An secant pile wall is often used for retaining walls, excavations or foundations. It consists of a series of bored piles that are driven into the ground close together so that their diameters overlap. The overlap results in a continuous wall that is both stable and watertight. The secant pile wall consists of primary and secondary bored piles. The primary pile is usually unreinforced, i.e. it does not contain any steel reinforcement. The secondary pile is drilled between the already installed primary piles. This pile is usually reinforced, i.e. it is provided with iron reinforcement. The reinforcement increases the stability and load-bearing capacity of the entire structure.
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Areas of application for the secant pile wall
Deep excavation pits
The secant pile wall is ideal for excavation pit closures, as it prevents the ingress of water and is highly stable. They prevent earth from slipping and water from entering the excavation pit. They also ensure a safe working environment.
Ensuring watertightness
If a high level of watertightness is required, for example near bodies of water or areas with a high groundwater table, the secant pile wall is particularly suitable for preventing water ingress. Secant pile walls are also often used in tunnelling due to their very high load-bearing capacity and to keep the groundwater out.
Lack of space and securing neighbouring buildings
In urban areas or where space is limited and traditional retaining walls cannot be erected, the secant pile wall offers a space-saving and efficient alternative. This enables construction projects to be carried out safely even in confined spaces. They also play a crucial role in securing adjacent buildings and infrastructure. Due to their design, which minimises vibrations and ground movements, they protect existing buildings from damage during construction work and ensure the stability of the entire construction site.
Advantages of a secant pile wall
Some advantages of the secant pile wall:
⇒ High stability
⇒ Water impermeability
⇒ Various sizes possible (pile diameter)
⇒ can be used in a wide range of soil conditions
Disadvantages of a secant pile wall
⇒ Low tolerances during production
⇒ Time-consuming construction
⇒ Cost-intensive depending on the construction project/requirements
Special challenges
Special challenges call for special solutions! When renovating a tunnel for rail traffic, two special features had to be taken into account. There had to be no water influence and the extreme pressure of the surrounding mountains had to be taken into account in the planning. The engineers and geologists opted for an overlapping bored pile wall, in which not only the secondary pile is reinforced but also the primary pile. A reinforcement cage with a smaller diameter was chosen for the primary pile so that the piles could still overlap.
Pile breaking of a secant pile wall
The Brextor® method is one method that can be used to process the secant pile wall. However, Brextor® can also be used to process all other types of pile walls, regardless of whether they are tangential or detached bored pile walls.
Brextor® offers you the following advantages:
🏗 Increased construction quality
Perfect pile breaking without cracks in the pile body or spalling on the pile outer skin, no bent or torn reinforcements and a height accuracy of +/- 1cm.
💵 Reduced construction costs
The demolition material consists of 80% gravel 0-30mm and can therefore be reused directly on the construction site. In addition, Brextor® requires less working space than conventional mining methods. This means that not only expenses for transportation and disposal incl. fees are saved, but the purchase and supply of replacement material is also eliminated. Furthermore, the preparatory work eliminates the need for a separating diamand cut at the final extraction level and the cleaning effort is massively lower than with conventional extraction methods.
⏱ Shortened processing time
For example, a pile with a diameter of 1 m and a height of 1 m can be processed within 40 minutes. A daily output of up to 16 piles is possible. In addition, Brextor® provides reliable performance and therefore increased planning security.
♻️ Environmentally friendly
With Brextor®, the demolition material (80% gravel 0-30mm) can be reused directly on the construction site. Brextor® also requires less working space. This saves excavation and replacement material. By reusing the demolition material directly on the construction site and saving on excavation and replacement material, transportation can be saved. In addition, landfills are less polluted.
👷 Increased health & safety at work
No heavy physical labor is required for pile processing, which massively reduces the risk of health hazards such as HAVS syndrome. Brextor® also avoids working in danger zones.
Are you ready for increased efficiency, safety and quality in your pile breaking projects?
Find out more about Brextor® here:
Contact us for more information and find out how you can benefit from this revolutionary pile breaking method. Call us on +41 41 495 05 20 or send an e-mail to info@brc.swiss. We look forward to working with you and taking your projects to the next level.