Find here below all our customers regulary questions about our techniques
Q&A on Bi-modulus columns
We can ensure continuity of the bi-modulus column at the interface. We carry out two main types of tests during the project, loading and stripping. That way we ensure the quality and quantity of the interface through visual inspection.
Q&A on Compaction grouting
Compaction grouting is a quasi-static process with controlled pressure and injection rates. There is therefore no risk of increasing pore water pressure nor generating post-construction settlement.
Q&A on Compaction grouting
Compaction grouting is a quasi-static process with controlled pressure and injection rates. There is therefore no risk of increasing pore water pressure nor generating post-construction settlement.
Q&A on Controlled Modulus Columns
Groundwater is no obstacle. We can build CMCs rigid inclusions where groundwater is present.
Our teams take extra care in this situation. The design is adapted accordingly in cases where the water flow through the soil is high.
Our company systematically controls cut-off to ensure the quality of the works. Cancelling risk of damage is our goal. This is why we systematically carry out earthworks according to best practices.
Q&A on Dynamic compaction
There are structures 20 meters from your worksite; can we use dynamic compaction?
We systematically monitor the vibrations generated on neighbouring structures throughout the project. If need be, we take preventive steps uch as reducing the height of release, installing vibration mitigation trenches. We sharply reduce the vibrations transmitted to neighbouring structures, even at less than 20 m.
For an urban or a small worksite, a Rapid Impact Compaction system can be cost-effective. The Rapid Impact Compaction technique allows us to compact the soil using the same technique as conventional dynamic compaction. The difference is that depths of treatment generally limited to about 5 to 6 meters.
Q&A on Dynamic replacement
It is possible to use dynamic replacement in organic soils. Dynamic replacement pilars combine to caracteristic features: large diameters (2 to 2.5 metres) and low slenderness ratio. This make dynamic replacement pilars suitable for treating very loose, waterlogged and highly organic soils.
Pre-excavating pilars is not necessary to carry out dynamic replacement. The initial pounding of the platform is generally sufficient to form the crater that initiates the dynamic replacement pilars. After filling this crater, pounding drives the “compacted plug” into the soil, which then serves as the basis for the formation of the rest of the pilar.
Q&A on Jet grouting
As a rule, jet grouting suits poorly to soils with blocks and rough gravel, to organic materials. It is not adapted either to soils through which large volumes of water flow.
Q&A on Menard Vacuum™
Menard Vacuum™ can substantially reduce consolidation time. Early pre-loading implemented as soon as the system is in place makes it possible. This goes without risk of ground failure.
How so? The vacuum generates an “artificial beam” between the horizontal drains and the membrane. The isotropic nature of the Menard Vacuum™ load combined with the “artificial beam” have a strong stabilising effect on the fill.
The technique is rarely used on surface areas of less than 10,000 m².
During the entire pumping operation, the Menard Vacuum™ maintains the water table at the level of the horizontal drain network. This process does not lower the water table within or around the worksite.
The vacuum pumps :
- only the volume of water expelled by the soil during consolidation settlement
- the residual flow necessary to maintain the vacuum.
Q&A on Rapid Impact Compaction
It is possible to compact the ground near an adjacent site with rapid impact compaction. Rapid impact compaction suits to ground improvement in small spaces. As an example, we can apply this technique within or next to existing warehouses. In such cases, we monitor very carefully vibrations in adjacent structures during rapid impact compaction.
Q&A on Slurry Wall
The slurry wall has virtually no mechanical strength. Therefore it cannot be used as a retaining wall. Slurry wall can be subject to erosion, so it cannot withstand large hydraulic gradients.
Q&A on Soil mixing
A wide variety of tools are available to choose from, depending on the application. For this type of application, you could for example use cutting tools to rapidly build wall or cell systems.
The binder is not always injected in liquid form. It is also possible to inject the binder either as a liquid slurry or as a dry powder.
The liquid slurry is injected by means of a pump. We talk about wet technique.
The dry powder is injected into the ground by means of compressed air. This is the dry technique. The water in the ground generates hydration and concrete setting.
Q&A on Stone columns
As a rule, stone columns shouldn’t be installed to address geotechnical issues related to load-bearing capacity and settlement in organic soils. Lack of lateral confinement and the risk of creep in organic soils do not make them suitable in that case. However, we can consider stone columns when the project is designed to provide drainage or slope stability.
Q&A on Vertical drains
Consolidation starts only when the preloading fill is placed.
The answer is clearly YES. But the real question is whether it is useful to drain soils that already has good drainage characteristics.
The main purpose of drains is to provide pore water with an escape path when the soil is subject to stressing due to preloading fill. Consolidation settlement takes place when pore water is removed from saturated soils. It is thus, as a rule, not necessary to install vertical drains if there is no water in the soil. This type of soil can be compacted directly.
Q&A on Vibrocompaction
The initial trial area defines the value precisely. However, as a general rule, vibrocompaction of fill placed hydraulically generates settlement amounting to 7 to 10% of the height of the soil treated.