The modern world of construction without the application of grouting techniques is hard to imagine. The main purpose of these ground improving techniques is to prevent damage to objects close to the building area and to seal soil and soil retaining constructions.
Grouting techniques are globally divided into the following subcategories:
• permeation grouting
• jet grouting
• compaction grouting
• compensation grouting
H5S offers its clients a full service in fracturing, compaction and compensation grouting. For permeation grouting, H5S is committed to installing PE-tubes and manchette tubes (TAMs) for the purposes of injection.
Example for compensation grouting
In an urban area, a deep construction pit is created with on one end tram tracks and the other side a shallow foundation. During the excavation of the pit, the retaining wall (sheet piles) will horizontally deform, causing settlements around the pit. As long as the deformations and settlements are within the calculated values and guidelines, there are – in principle – no further steps to take. Whenever the expected settlements exceed in a way that they can cause damage to the tram tracks and shallow foundations, it is possible to apply compensation grouting.
The application of compensation grouting starts with the installation of Tubes a Manchettes (TAMs). TAMs are (often) steel pipes with small openings every 30 centimetres. The TAMs are installed in the ground through sonic drilling under the tram tracks and shallow foundation. Around the installed TAMs, dämmer is applied. The system is now set up.
During the excavation, a surveyor executes height measurements at different points around the sensitive objects. When the measurements show settlements within the soil, the TAMs will be injected with grout mortar. The moment injection starts is predetermined based on the degree of settlement.
Any groundmass that relaxes during excavation works is re-tensioned using compensation grouting. The compensation grouting takes care of stabilising the settlement and eventually sets the settlement back to the original level. The process above is repeated throughout the excavation process to ensure that the settlements are within the allowed values.
H5S has, in this way, lifted a large diameter pipeline, tram tracks and a shallow foundation to its desired level.
Does one of this techniques fit your project? Please contact us.