Widening cuttings in rocky terrain, to make way for additional railway tracks or motorway lanes, employs systematic operation keeping existing way clear

摘要

Successive vertical slices (1) of the section to be widened, are broken down, starting from the base and working upwardly, with the objective of keeping the existing track or road clear for uninterrupted, interference-free flow of traffic. The region (5) below the upper sections (2) is first broken down and removed, leaving space (4) for successive collapse and clearing of rock from the upper sections. The horizontal or inclined rock strata in the body of stone, are drilled (3) to a horizontal depth corresponding with the length of each slice removed. A known, prepared, non-explosive rock-breaking agent is charged into each hole. This becomes hydrated, developing pressures in the rock, which fracture it. The fractured rock falls into the space below, under its own weight. Advanced technology is used to clear the rock away.