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 overlapping results in a continuous wall that is both stable and watertight. The secant pile wall consists of primary and secondary 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.
Content
Areas of application
Deep excavation pits
Secant pile walls are ideal for excavation pit closures, as they prevent the ingress of water and are 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, secant pile walls are 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, secant pile walls offer 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 neighbouring 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
Some advantages of secant pile walls:
⇒ High stability
⇒ Water impermeability
⇒ Various sizes possible (pile diameter)
⇒ can be used in a wide range of soil conditions
Disadvantages
⇒ Low tolerances during production
⇒ Time-consuming construction
⇒ Cost-intensive depending on the construction project/requirements
Special challenges
Special challenges call for special solutions! Two special features had to be taken into account when renovating a railway tunnel. 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 decided in favour of a secant 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
One method with which overlapping bored pile walls can be processed is the Brextor® -Method. 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. In addition, Brextor® requires less working space. This saves excavation and replacement material. Due to the direct reuse of the demolition material on the construction site and the saving of excavation and replacement material, transports can be saved. In addition, landfills are less burdened.
👷 Increased health & safety at work
No heavy physical work is required for pile cutting, which massively reduces the risk of health hazards such as HAVS syndrome. In addition, Brextor® 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 email to info@brc.swiss. We look forward working with you and taking your projects to the next level.
