Geotechnical services

Drainage Construction Company Tolos is one of the national leaders in geotechnical services. Our core business is the protection of deep excavations by driving steel sheet piles, steel sections and building Berliner walls in different technologies.

Driving of steel sheet piles

Walls made of steel sheet piles are a common method of protection of deep excavations. They protect the excavation against land sliding, inflow of groundwater, as well as the nearby structures against settlement. The walls are built by hammering the piles using vibrating hammers, and in case of objects sensitive to vibration we use the hydraulic presses which produce virtually no vibration.

Jet Grounting

Jet Grouting is the process of strengthening the subsoil by mixing the soil with the grout extruded under high pressure. It is a popular method of strengthening the foundations of the existing buildings, squares made of reinforced concrete slabs and creating solid walls of excavations. Jet Grouting may be applied in almost all soil conditions and used for building reinforcements in indoor spaces.

Displacement piles FDP, SDP, CMC

Piles are an effective means of strengthening soil, displacement piles provide a much larger load capacity than drilled piles of the same diameter and length. The special design of the drill results in a lack of aggregation of material during drilling process, and thus densification of the soil. In the longer term it limits the use of concrete and significantly accelerates the piling process.

CFA/FSC piles

The piles are drilled using a popular method of strengthening cohesionless soils with a high degree of compaction. The drill is driven to the desired depth, whereupon concrete is forced-in without prior removal the drilling tool. Due to the resulting high pressure we get a very good contact between the pile and the soil.

Berliner walls

Berliner walls are another effective method of protection of deep excavations. The process involves the formation of timber, steel or concrete lining between the driven steel piles. The main advantage of this method is the ability to recover part of the materials used for building the protection and re-use them elsewhere.

DSM columns

DSM columns are used in cases where it is necessary to strengthen the surface layer of the substrate (e.g. silt or sandy soils). The column is created by mixing the soil with concrete grout to prevent aggregation of material. It also limits the vibration which makes it suitable for use in the vicinity of existing structures not resistant to vibration.