Water supply of the Vasilevsky island

Within construction of the water supply system to the Western part of Vasilievsky Island in Saint-Petersburg one press-auger boring machine and two HDD machines were involved.

For placement of drilling facilities at sites in the over-water length of the Neva river close to the Petrovskaya and Arsenalnaya embankments according to calculations of the "SP VIS-MOS" specialists two temporary heavy-duty artificial platforms were built.

The works were carried out in two stages. At the first stage consecutively from the Petrovskaya and Arsenalnaya embankments Ø1420mm pipes (conductors) were pressed by the press-auger boring machine into the bottom of the Neva river. They had to serve as a guiding casing for a drill string at the stage of pilot drilling and at the stage of borehole widening, as well as for the pipeline string at the stage of pipeline pulling process.

Within the second stage two HDD machines were involved. Difficulty of drilling operations consisted in necessity to get from the outlet conductor with the drill string into the input conductor. This task was successfully completed with the help of steering equipment and skill of the operators. Then the borehole was consecutively expanded up to Ø1350 mm, and the Ø1000mm bottom pipe was pulled into it.

In the covered with ice Neva river along the embankment was made a lane into which was laid a bottom pipe and thus pulling the onshore line of the pipeline made right from the water surface. Due to the fact that the borehole was prepared perfectly, pulling of the string took minimal effort of the drill rig and construction stage was made without technical difficulties.

At the final stage of construction accumulated by the company "SP VIS-MOS" rich practical experience allowed to complete the project successfully with installation of a ‘river’ line string from the Arsenalnaya to the Petrovskaya embankment.

http://vis-mos.ru/ru/press/publications/detail/1032/