Alternative method of trenchless pipe installation - Short Arc Pipe
One of the options in constructing tunnels, particularly in crossing under watercourses or in the densely populated areas, is the crossing into a vertical arc with small radius. Until recently it was impossible to execute a crossing underneath a watercourse with a smaller radius than the flexible radius of the gas pipe. The known technologies operating within the limits of a flexible radius are the Horizontal Directional Drilling (HDD) and the Direct Pipe. The technology called “Short Arc Pipe” enables pushing gas pipes directly without using any duct pipes and without the need for deep jacking or exit pits. Being able to push pipes into the tunnels with small radiuses means also shorter distances under the rivers, highways or other obstacles using either segment welded pipes or pre-bended pipes. All of this can be achieved chiefly as a result of a precise control of the pushed pipe. This technology was used for the first time in Slovakia, during a gas pipe crossing coming from a bridge and leading underneath a river. Using this technology a trenchless crossing was constructed with four times smaller radius than the used flexible radius of the 48’’ pipe is. “Short Arc Pipe” enables to undertake HDD and Direct Pipe crossings that were formerly not possible to execute, mostly due to the length of the drilling distances.

Marián Krčík, Hydrotunel, s.r.o.
Engineering of the Slovak University of Technology in Bratislava graduate. Since the end of his studies since 1986 he has been professionally interested in tunneling and drilling machines. Since 1997, the founder and the owner of HYDROTUNEL, a construction company that uses trenchless technologies to execute the projects; e.g. microtunnels, collectors, waterways. The designer of several tunneling machines and the equipment for trenchless technology. Patents have been issued to some of them.