Steel pipe pile driving type foundation

C-LESS foundation

Support structure for decks and zigzag bridges

C-LESS foundation


C-LESS foundation method is a simple foundation method for small-scale structures such as decks, wooden footpaths, and zigzag bridges.

It is a construction method that obtains the bearing capacity required to support the structure with steel pipes driven in multiple directions (4 standard, 6 maximum), and is a foundation construction method that does not use any concrete.

The foundation is lightweight and compact, weighing approximately 12 kg, and can be installed manually. In addition, since it does not use heavy machinery, it can be installed without excavating the ground, and it is an environmentally friendly construction method such as ecosystem protection.

This method can improve the life cycle of structures by combining with materials such as plastic wood, synthetic wood, aluminum alloys, and steel materials.

Structural drawing / schematic drawing

Member details

  C-LESS foundation member composition Weight Material
1 Guide plate 6kg Steel material
(hot-dip galvanizing)
2 Connecting metal fittings 6kg
Total Per C-LESS foundation 12kg

Construction examples

Construction procedure


deck using C-LESS foundation


C-LESS foundation is a compound word of “LESS” that does not require concrete “C”.

C-LESS foundation is a concrete-free foundation and has the following features.

1. Lightweight

C-LESS foundation has a structure that combines a steel guide plate and steel pipe piles, and it maintains sufficient strength as a foundation for decks, etc., even though a guide plate is extremely lightweight at only 6 kg, which can be carried easily by hand.

2. Easy construction

Since this method was developed for soft ground or sloping ground where heavy machinery cannot be used, steel pipe piles are basically installed manually.

By using a lightweight machine such as an electric hammer for installing, workability will be good under any circumstances.

3. Select the number of piles according to the site situation

The standard number of steel pipe piles is 4, but it can be selected from 3, 4, 5, and 6 according to the terrain and ground conditions. The length of the steel pipe pile is determined by examining the structure according to the number of piles.

In addition, the guide plate has 6 guide pipes for driving steel pipe piles, and if there is an obstacle such as gravel, the driving holes can be changed and re-driving or additional driving is possible.

4. Environmental performance

The guide plate of C-LESS foundation does not require large-scale excavation work because it has only 300mm as an outer diameter. In addition, since steel pipe piles are driven directly into the ground, it is a nature-friendly construction method suitable for environmental protection.

5. Durability

C-LESS foundation is rust-proofed by hot-dip galvanizing on both of the guide plate and the steel pipe pile, and has excellent durability against corrosion, chemicals, and ultraviolet ray.

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