Dynamic loads and vibrations: a source of damage
Factory equipment that involves rotation, reciprocation, or impact almost always generates dynamic loading, which can undermine foundations particularly on loosely compacted soils as well as generating significant vibrations. These vibrations can affect precision machinery or employee comfort through noise and resonance issues and also lead to structural fatigue in supports. The nature of damage caused by the vibrations or sound waves moving through the ground from areas of cyclic loading is directly related to the peak particle velocity (PPV), which is a standard measure of vibration; thresholds for damage typically start around 5–10 mm/s.
Dynamic loads and vibrations: a source of damage
Factory equipment that involves rotation, reciprocation, or impact almost always generates dynamic loading, which can undermine foundations particularly on loosely compacted soils as well as generating significant vibrations.
These vibrations can affect precision machinery or employee comfort through noise and resonance issues and also lead to structural fatigue in supports.
The nature of damage caused by the vibrations or sound waves moving through the ground from areas of cyclic loading is directly related to the peak particle velocity (PPV), which is a standard measure of vibration; thresholds for damage typically start around 5–10 mm/s.
Brick, unreinforced masonry, and historic buildings are more vulnerable than reinforced concrete or steel structure and soft or loose soils amplify vibrations more than dense soils or rock, noting the vibration intensity drops rapidly with distance. If the frequency of vibrations matches the natural frequency of the building, amplification can occur, increasing the risk of damage.
Even if structural damage does not occur the vibrations can cause distress to residents and create a Statutory Nuisance issue, noting people can often detect vibrations at peak particle velocities (PPV) as low as 0.15 mm/s. There could also be breaches of environmental legislation, if vibrations are persistent and unreasonably interfere with the use or enjoyment of private property.
Impact on infrastructure
Rail
The cyclical loading caused by train traffic can cause the track bed to settle and lose support, leading to track faults, speed restrictions, and ongoing maintenance. Vibrations emanating from rail tracks have also been known to create nuisance issues.
Bridges
The constant dynamic load on bridge foundations can cause ground settlement and fatigue, compromising the long-term integrity of the structure.
Other Infrastructure
Factory equipment that involves rotation, reciprocation, or impact almost always generates dynamic loading, which can undermine foundations particularly on loosely compacted soils as well as generating significant vibrations.
Roads
The cyclical loading caused by road traffic and particularly heavy goods vehicles can lead to the excessive settlement of the granular sub-bases beneath flexible and concrete pavements.
This results in cracking and breaking of concrete pavements and rutting of flexible pavements which increases the risk of wearing course degradation and formation of potholes.
This can greatly affect the performance of the road and ultimately lead to extensive repairs and the associated disruption and travel chaos caused by extensive road closures.
Rocking of concrete slabs can occur if the sub base has been differentially eroded, this can also create a nuisance with associated ground vibrations caused every time a vehicle passes over a rocking slab.
Geobear's approach to loading and vibration
Geobear's Ground improvement treatment is a highly effective, non-disruptive alternative to traditional excavation and replacement.
Instead of digging out and replacing the affected ground, we use geopolymer injection to densify and strengthen the sub-base from below.
In addition, Geopolymers have the ability to adsorb vibrations due to their cellular structure and so can be used to dampen ground vibrations.
Densifies the ground
We inject a high-strength geopolymer that fills voids and compacts the soil, increasing its density and making it more resistant to future vibration.
Provides a stable foundation
The newly strengthened ground provides a long-lasting, stable foundation that can better absorb and dissipate the cyclical loading from traffic.
Is up to 70% faster
The entire process can be completed in hours or days, not weeks or months. This dramatically reduces downtime.
Provides a proven track record
We have a wide portfolio of completed projects and engineering expertise available to support you on projects of any scale.
