TRENCHLESS WORKS

Horizontal directional drilling

This method is most often used when installing non-gravity engineering and utility networks under over ground construction works, roads and railroad tracks, rivers as well as other water bodies.

Polyethylene, steel and special cast iron pipes are laid with the help of horizontal drilling equipment.

Special steel, polymer concrete, fibreglass and ceramic pipes are laid with the help of microtunneling equipment.

Microtunneling allows the laying of pipes from 200mm to 2,000mm and more in diameter.

Microtunneling

This method is used in the construction of gravity engineering and utility networks or when installing utility tunnels.

It is also applied when special precision is required and the conditions are really complicated due to infrastructural or geological factors.

Pipe ramming

This method is used to install steel casing ducts for various engineering and utility networks under roads, railroad tracks or ramparts. 

Steel pipes from 200mm to 1,400mm in diameter are laid with the help of pneumatic pipe ramming equipment.

Pipe jacking

This method is used to install steel casing ducts for various engineering and utility networks under roads, railroad tracks or ramparts.

Steel pipes from 300mm to 1,400mm in diameter are laid with the help of hydraulic pipe jacking equipment.

Sliplining

This method is used for the renovation of badly rundown pressure and gravity pipelines, when operating conditions allow for a significant decrease in the diameter of the old pipe.

Polyethylene, polypropylene and fibreglass pipes are placed in old pipes with the help of sliplining equipment.

Pipe bursting / cracking

This method is used for the renovation of badly rundown pressure and gravity pipelines, when operating conditions do not allow for a decrease in the diameter of the old pipe and, on the contrary, require for it to be increased.

The old pipe is cracked with the help of static or dynamic pipe cracking equipment and instead new polyethylene pipes of the same or bigger diameter are inserted.

Swagelining

This method is most often used for the renovation of badly rundown gravity pipelines, when operating conditions allow for a small decrease in the diameter of the old pipe. Before the insertion into the old pipe, the diameter of a new pipe is reduced and later restored to its nominal diameter.

Swagelining can be performed both at the construction site and at the plant.

Swagelining at the construction site: new polyethylene pipes are reduced with the help of a special calibration device until their diameter is smaller than the interior diameter of the pipe under renovation and are then towed into the old pipe with the help of hydraulic towing machines.

The inserted pipes restore their nominal diameter due to the “material memory” effect and adhere closely to the walls of the old pipe. Pipes of up to 1,100mm in diameter can be renovated in this way. Swagelining at the plant: during the manufacturing process, a pipe is folded lengthwise into a so called “U” or “Ω” shape and is rolled. At the construction site, a pipe is towed into the pipe under renovation with the help of a towing crane and is then inflated until it reaches its nominal diameter with the help of hot steam pressure. As the result, the new pipe adheres closely to the walls of the old pipe. Pipes of up to 500mm in diameter can be renovated in this way.

Cured-in-place pipe lining (CIPP)

This method is used for the renovation of deteriorated gravity and pressure pipelines, when operating conditions allow for a minimal decrease in the diameter of the old pipe and when mechanical pipe resistance must be restored.

The method is highly effective in such sites where earthmoving works are either unwanted or impossible.

An epoxy resin-saturated felt tube “sleeve” is pulled into a damaged pipe and is then inflated and cured. After the curing, the liner hardens and can be exploited as a new pipe. Curing can also be performed with the help of hot water or steam, or UV radiation.

Curing with UV radiation: a binding material of a liner is fibreglass reinforced plastic impregnated with polyester and/or vinylester resin. Curing is caused by certain resin particles reacting to UV light. The material is highly resistant to deformation, thus the smallest possible reduction in the diameter of the pipe under renovation is guaranteed. Pipes from 150mm to 1,600 mm in diameter can be renovated with the help of this curing method.

Curing with steam or hot water: a binding material of a liner is synthetic fibre impregnated with resin that reacts to heat. The material resistance to deformation is three to four times lower compared to fibreglass, therefore the diameter of the pipe under renovation decreases more than when the UV technology is applied. Pipes from 150mm to 2,000mm in diameter can be renovated with the help of this curing method.

Spiral wound pipeline rehabilitation (SPR)

This method is used for the renovation of various profile gravity sewer and storm drain pipelines in order to improve their hydraulic efficiency and restore mechanical resistance. Taking into consideration the imposed requirements, various profile strips made of PVC or HDPE are employed. Special winding machines spirally wind the strips into a liner directly into the deteriorated pipe. Pipes from 150mm to 5,500mm in diameter can be renovated with the help of this method depending on the shape of a pipe, a strip profile, composition and the winding technique.

Pipe coating

This method is used for the renovation of corroded but not yet deteriorated steel and cast iron pipelines in order to increase their service life and improve the quality of water.

Cement and epoxy resin mixtures are used for the coating of interior pipeline surface.

Manhole coating

This method is used for the renovation of old reinforced concrete manholes in order to increase their service life and ensure their impermeability.

The interior surface of a manhole is coated with cement or epoxy resin mixtures with the help of special high pressure machines.