Non-explosive rock removal stands for the controlled loosening and fragmentation of rock without the use of explosives. The method is used wherever vibrations, noise and exhaust gases must be minimized, such as in densely built urban areas, sensitive infrastructures, tunnels, or geologically complex settings. The focus is on mechanical-hydraulic methods that split rock along prepared rows of boreholes or remove it edge by edge (edge demolition). In practice, this frequently involves the use of hydraulic rock and concrete splitters together with matching hydraulic power units; at interfaces to structures, concrete pulverizer can also be useful when rock and concrete are monolithic or interlocked.
Definition: What is meant by non-explosive rock removal
Non-explosive rock removal encompasses all approaches by which rock structures are reduced, released, or removed to shape without explosives. A typical application is hydraulic splitting technology: split cylinders are placed into boreholes and, via the wedge principle, generate controlled cracks. The process features low vibration levels, is highly controllable, and produces fracture surfaces along defined lines. The measure is suitable in confined spaces, in water protection areas, in excavation pits next to existing buildings, in tunnel heading in delicate geologies, and for preparing connection faces to structures. In contrast to sawing and milling, splitting overcomes material strength by locally applied compressive forces, allowing blocks to be released systematically.
Methods and working principles
The basic principle of splitting technology is based on high, radially acting forces generated in the borehole by hydraulically actuated wedges. These forces exceed the tensile strength of the rock and drive crack fronts along natural weaknesses (joints, bedding planes) or along the planned hole pattern. Split cylinders are dimensioned according to the geometry and strength of the rock as well as the desired block format. The heart of the system is hydraulics: hydraulic power packs provide flow and pressure, and the splitting devices convert this energy into controlled deformation work. Where rock transitions into structural areas, concrete pulverizer are additionally used to detach cantilevering concrete parts, anchor heads or linings before continuing with rock release.
Rock analysis and planning
Robust planning begins with geological assessment: rock type, grain bonding, joint orientations, degree of weathering, and water flow determine the appropriate hole pattern and the choice of splitting tools. Particularly important is aligning the drillings with the preferred crack direction; this reduces force demand, drilling meters and cycle times. In hard rock with high compressive resistance, smaller hole diameters with a tighter grid are preferred; in layered or jointed rock, a coarser grid can suffice. For mixed tasks—rock meets concrete—the transition should be planned so that concrete pulverizer handle near-structure dismantling steps while split cylinders release the rock volume in a controlled manner.
Tools and equipment for non-explosive rock removal
The selection of equipment is based on geometry, accessibility and material properties:
- Hydraulic splitter: Hydraulic split cylinders for boreholes; high splitting forces with low emissions. Suitable for rock and—if required—for massive concrete. Rock splitters.
- Hydraulic power pack: Power supply for the splitters; modularly matched to performance and the deployment environment, e.g., in tunnels or city centers.
- Concrete pulverizer: For edge demolition, exposing connection reinforcement, and detaching concrete that covers or interlocks with the rock.
- Attachment shear and multi cutters: For cutting mixed materials around the rock removal area, e.g., inserts, utility line components or light steel sections.
- Steel shear and cutting torch: For peripheral tasks, such as removing steel components or vessels in the work area to create access to the rock.
Drilling technology and hole patterns
The hole pattern defines the subsequent fracture line. Criteria include hole diameter, center spacing, staggering and edge distances. Drilling depth generally matches the planned removal lift; a slight inclination can help guide crack fronts. In compact rock, evenly distributed rows are advantageous, while in jointed rock, aligning along joint systems boosts efficiency. Clean borehole cleaning is crucial to allow split wedges to act concentrically. Where structural components overlap with rock, concrete pulverizer can be used in advance to remove overlay concrete, shotcrete or leveling layers to optimize drilling in rock.
Application areas at a glance
Concrete demolition and special demolition
At component–rock interfaces, rock is often reduced without blasting to relieve structures or to create new foundation slabs. Concrete pulverizer handle edge-near demolition, while split cylinders release the rock mass block by block.
Building gutting and cutting
In complex existing structures with rock embedment, e.g., during underpinning, non-explosive rock removal supports the building gutting. Cutting edges are prepared with splitting; utility lines and built-in components can be removed with attachment shear or multi cutters.
Rock excavation and tunnel construction
In tunnel and gallery works, splitting devices are used in sensitive sections, during periods with vibration restrictions, or near existing structures. Removal proceeds in stages; emissions remain low, which simplifies occupational safety and construction logistics.
Natural stone extraction
For quarrying, splitting is used to release raw blocks along desired formats. Precise hole-pattern planning and alignment with natural bedding determine quality and yield.
Special applications
In protected areas, water intakes, or in the immediate vicinity of sensitive installations, low-vibration methods are often prescribed. Splitting minimizes far-field effects, dust and noise; additional measures such as mist binding or coverings improve immissions control.
Workflow: step by step
- Survey and documentation of geology, utility lines and boundary conditions.
- Definition of the hole pattern and removal stages, including access and laydown areas.
- Drilling works with compliant execution in terms of dust removal and water management.
- Insertion of split cylinders, controlled activation of hydraulics, release of blocks.
- Rework: lifting, sorting, size reduction; at structure edges, if necessary, use of concrete pulverizer.
- Securing the exposed faces (rockfall net, shotcrete, rock bolt) based on the structural concept.
Performance factors and cycle planning
Performance is determined by rock strength, hole pattern, accessibility, block handling, and hydraulic output. Short routes for removal (haulage logistics), optimized drilling meters per cycle, and suitable block sizes increase throughput. A well-coordinated interplay of hydraulic splitter and hydraulic power packs directly impacts cycle times.
Occupational safety and emissions
Even low-vibration methods require comprehensive protective measures: control of drilling dust and water, safe handling of the hydraulic hose lines, stability of removal lifts, and controlled fall direction of released blocks. Personal safety equipment, exclusion zones, and clear hand signals are mandatory parts of execution. Noise and dust can be reduced by appropriate drilling technology, dust extraction, or mist. Legal requirements for labor and environmental protection are location-dependent and must be observed.
Quality assurance and documentation
Structured documentation of the hole pattern, applied pressures, removal stages, and the material flow enables continuous optimization. Visual inspections of fracture surfaces and regular checks of tools as well as the hydraulic connections ensure execution quality. At transitions between rock and concrete, seamless recording of the interfaces is important to allow subsequent trades to connect precisely.
Environmental and disposal aspects
Non-explosive rock removal reduces vibrations and secondary immissions. Nevertheless, water and soil protection, dust suppression, clean construction waste separation between rock, concrete and steel, and short transport routes are important. Reuse of aggregates as backfill or frost protection material is possible after suitability testing. Additional requirements often apply in protected areas; these must be considered on a project-specific and general basis.
Limits and combination with other methods
For very large volumes or extremely high strength, a combination of splitting, sawing and selective chiseling can be expedient. Splitting creates defined crack lines along which other methods can proceed in a material-friendly way. In construction areas with reinforcement and embedded parts, the targeted use of concrete pulverizer, attachment shear or steel shear supports the process without losing the advantages of non-explosive removal.
Practice-oriented notes on selecting equipment
Essential is the coordination of hole diameter, split cylinder and hydraulic output. In tight spaces, compact hydraulic splitter are advantageous; along long removal fronts, multiple cylinders can be operated in a staggered sequence. Proximity to structural components often requires additional concrete pulverizer to define intended fracture lines cleanly. Early integration into work planning reduces downtime and rework.