Building roads through stone and rock.

Before commencing the actual road building operation, the prerequisites for doing so need to be established first. Heavy equipment is used where roads are to be built on rocky ground. How to create a precise ground level in hard rock? What are the methods used?

Hard rock to the core

Road builders are confronted not only with subsoils that are excessively soft or instable, but also with bases that are extremely hard – too hard for roads to be built to the specified level without preparing the ground first. This difficulty typically arises when a road is to be built in mountainous terrain or in other areas where the ground is rocky or extremely hard. When that is the case, routing operations need to be carried out first.

Cutting through rock with no explosion, no dust

Routing operations are frequently carried out on ground which consists of limestone, slate, or granite, but also in other types of rock. Blasting is a common method for removing hard rock, and is accompanied by the inevitable nuisances of noise, dust, and heavy vibrations.

Being gentle on the mountains

Where blasting is not feasible because houses, industrial estates or railway lines are located in the immediate vicinity of the job site, routes are often produced by cutting through the rock with surface miners. This environmentally friendly method is capable of cutting rock without causing any damaging vibrations and is therefore gentle both on the mountains and on their inhabitants.

Carved in stone with pin-point precision

Routing operations involve cutting a path through hard rock. Surface miners cut the rock by means of a cutting drum fitted with tungsten carbide tools, and load it onto trucks or dumpers via their slewing discharge conveyor, all in one single working operation.

Reusing the cut material

The cut material is of uniform size and can therefore be reused as backfill without requiring additional treatment. Surface miners produce a clean and precisely levelled surface which is ideally suited as a base for the road to be built.

Producing a stable floor in the tunnel

Routing operations in tunnel construction are no different from those in open terrain. Drilling or blasting of the tunnel tube creates an uneven floor surface that needs to be both lowered and levelled. The same method is applied when lowering the floor of an existing tunnel for the purpose of increasing the tunnel’s headroom. Surface miners remove the existing rock layer by layer until a clean and stable floor surface has been produced, enabling the construction work to continue on a precisely profiled ground level.