The ground beneath the M1 motorway is being reinforced using piles of varying diameters depending on the soil layer

In a recent post on his social media page post on his social media page, he presented the MKIF introduced Keller piling, which is also being used in the M1 motorway extension.

Photographs were used to illustrate the piling work, which serves as a preparatory phase prior to embankment construction to reinforce the subsoil where measurements indicate this is necessary. The photographs taken at kilometre 57 clearly illustrate how the technology works:

The aim of „deep compaction with gravel addition” – as it is officially known – is to improve the parameters of non-load-bearing subsoil to the required extent during soil improvement: gravelly, loose soils are compacted, whilst in water-saturated cohesive soils, gravel is pressed in to accelerate their dewatering and consolidation – they write.

The size of the piles is adjusted according to requirements and soil conditions

Although the average diameter of the gravel piles is 50–60 cm and their depth is 5–8 metres, these figures are not fixed: they are adjusted according to the soil conditions.

This is because the horizontal „vibration force” drives different quantities of stone into the ground depending on the compactness of each soil layer; consequently, the pile diameters vary from one soil layer to the next. It drives fewer stones into denser soil and more into looser, softer soil. This is how a homogeneous bearing capacity is achieved in the improved subsoil.

Without any environmental impact

We lower the so-called vibrator into the pre-drilled holes, then pull it up a few decimetres whilst feeding the additive into the soil through the chute, right up to the tip of the vibrator. When it is lowered again, the vibrator presses the additive sideways into the soil and compacts it.

To achieve the correct compaction, the vibrator’s current consumption must be within the range of 80–100 amperes.

It is particularly important to note that the Keller gravel piling method has no harmful environmental impact whatsoever. It involves introducing naturally occurring gravel into the ground, which, when compacted, makes the substructure load-bearing without altering the original environmental conditions in any way.