rörbrottsbrytning

Rörbrottsbrytning is a rock fragmentation technique used in mining and civil engineering in which rock is broken through controlled pressure transmitted via a tube inserted into a borehole or series of boreholes. The objective is to create orderly fracturing around the borehole to enable removal of rock with minimal blasting energy, reduced vibrations, and improved control over the fragment size.

The method typically involves preparing a borehole pattern and inserting a sealed pipe or series of pipes. Depending on the variant, the pipe is subjected to hydraulic expansion, mechanical loading, or an internal explosive sequence that drives the pipe and surrounding rock to crack along predetermined paths. The induced fractures propagate from the borehole, producing a network of cracks that breaks the rock into manageable blocks for subsequent excavation.

Rörbrottsbrytning is applied in situations where conventional blasting is undesirable due to vibration-sensitive surroundings, the need for precise fragmentation, or environmental concerns such as ground stability and dust control. It is commonly used in tunneling, underground excavations, and restricted-access rock faces adjacent to infrastructure. The technique tends to be slower than blasting and requires specialized equipment, careful planning, and skilled operators. Rock quality and existing natural fracture systems influence its effectiveness.

Safety considerations emphasize controlled expansion, stabilization of boreholes, rock mass support, and coordination with ventilation and dust management. While related to other rock-splitting and hydraulic expansion methods, rörbrottsbrytning forms part of a broader set of tools for rock fragmentation, chosen for specific project constraints and geotechnical conditions.