Rock cutting/processing is a core field in civil engineering, tunnel construction, special foundation engineering, in natural stone extraction and at interfaces between rock and structures. It comprises loosening, shaping and reducing rock to transportable sizes or to specified dimensions – precisely, in a controlled manner and ideally with low vibration levels. Especially in sensitive environments, such as inner-city settings or near protected building fabric, non-explosive rock removal is used. Here, hydraulic splitting with hydraulic rock and concrete splitters plays a key role. In combined tasks where rock masses and concrete structural members meet, concrete demolition shear as well as other hydraulic tools can be integrated into the process. This contribution examines definition, methods, areas of application, planning and safety – with particular focus on proven, non-explosive procedures and their embedding in professional workflows.
Definition: What is meant by rock cutting/processing
Rock cutting/processing refers to the entirety of methods used to loosen, remove, structure, break down into transportable pieces or bring natural rock to dimension. These include in particular drilling, splitting, cutting, milling, chiseling and secondary crushing. The objective is controlled modification of the rock mass along planned separation planes, while complying with specifications for vibration, noise, dust, stability and dimensional accuracy. While blasting is often used in remote areas, in sensitive zones non-explosive rock removal methods such as hydraulic splitting with rock and concrete splitters prevail. Where rock and concrete structures are tied together, concrete demolition shear complement the sequence, for example when separating foundations, shotcrete shells or anchor head areas.
Methods and procedures in rock cutting/processing
The choice of method depends on geology, location, environmental requirements, construction logistics and target geometry. In practice, a combination of procedures has proven itself: drilling for preparation, hydraulic splitting for crack initiation and guidance, followed by secondary crushing, sorting and haulage logistics. Sawing, milling or chiseling are additionally used when defined edges, smooth separation faces or profile adjustments are required.
Hydraulic splitting with rock and concrete splitters
With hydraulic splitting, a borehole is drilled and a splitting cylinder is inserted. Hydraulic pressure generates wedge forces that initiate cracks in the rock and guide them in a controlled manner. Advantages are low vibration levels, low noise emissions and very good controllability of the fracture line – properties used in rock excavation and tunnel construction, in natural stone extraction as well as in special applications with strict requirements. Appropriately sized hydraulic power units supply the splitters with the necessary pressure and flow rate; precise sizing reduces cycle times, protects equipment and increases process reliability.
Drilling as preparatory work
The drilling pattern sets the framework for splitting forces and crack propagation. Key parameters are hole diameter, depth, spacing and orientation relative to natural jointing. Cleaned boreholes and precise positioning are crucial to minimize friction losses and to transmit wedge forces effectively into the rock mass. In water-bearing zones, flushing and dewatering concepts must be planned to ensure the effectiveness of the splitting technique and the safety of the worksite.
Mechanical cutting and sawing
Wire sawing and cutoff saw methods are used when dimensionally accurate separation faces and defined edges are required, for example for block extraction or precise openings in rock faces. In areas with concrete–rock transitions, this produces clean cut surfaces that are subsequently further processed by splitting or by using concrete demolition shear.
Milling and chiseling
Rotary milling cutters and chiseling tools are used to create profiles, smooth contours or remove softer rocks. These methods must be selected based on the material, as they can produce higher vibrations. In tunnel construction and special demolition, they are used specifically where rock surfaces must be refined or geometrically adjusted.
Thermal and waterjet methods
Flame jetting and high-pressure water jetting are niche methods for specific rocks or surface requirements. They require separate occupational safety measures as well as careful assessment with regard to emissions, water treatment and permits. As a rule, they are combined with the mechanical and hydraulic methods mentioned above.
Areas of application and typical tasks
Rock cutting/processing ranges from small profile adjustments to large-volume rock removal. The focus is on rock excavation and tunnel construction, natural stone extraction, tasks at concrete–rock interfaces in concrete demolition and special demolition, precise strip-out and cutting in existing structures with rock contact as well as special applications under confined or particularly sensitive boundary conditions.
Rock excavation and tunnel construction
In the excavation of adits, cross passages or emergency bays, controlled crack guidance is essential. Hydraulic splitting with rock and concrete splitters enables low-vibration excavation along predefined lines, reduces the risk of subsequent rockfalls and protects adjacent structures. In tunnels with shotcrete lining, concrete elements can be removed with concrete demolition shear before the rock is split in a targeted manner – clear separation of tasks increases safety and quality.
Natural stone extraction
When extracting blocks of granite, limestone or sandstone, low cracking and dimensional accuracy are key quality criteria. Aligning the drilling and splitting pattern with joints and bedding, paired with moderate splitting cycles, ensures high edge quality and minimizes reject rates. The non-explosive approach also facilitates compliance with noise control and environmental protection requirements in the surrounding area.
Concrete demolition on rock masses
In anchor zones, foundation interfaces or leveling layers, concrete and rock meet. Concrete demolition shear separate concrete bodies, release reinforcement and create space so that the rock can then be processed using splitters. Steel shear or hydraulic shear are added when anchors, brackets or beams must be removed. In this way, the composite is released step by step, safely and material-specifically.
Strip-out and cutting in existing structures with rock contact
In building adaptations within existing structures, floor plan interventions often encounter in-situ rock. Saws for precise openings, concrete demolition shear for concrete components and the subsequent splitting of the rock form an optimized process chain that limits vibrations, controls dust exposure and protects the structural integrity of the existing structure.
Special applications
In alpine locations, near sensitive facilities or where vibration thresholds are strictly limited, non-explosive procedures are often the only option. Rock and concrete splitters deliver controllable results even in hard-to-reach situations. Redundant energy supply using suitable hydraulic power packs and clearly defined emergency procedures increase operational safety.
Geology, fracture mechanics and drilling pattern
Rock properties are the key to predictable crack behavior. Grain bonding, anisotropy, jointing, water content and bedding dip control how splitting forces act. From this, hole diameter, depth, spacing and wedge orientation are derived. The goal is to use the natural weakness structure and steer cracks so that defined, stable fracture bodies are produced.
Rock types and their behavior
Igneous rocks (e.g., granite, basalt) are usually hard and brittle and reward precise drilling patterns with clean fracture faces. Metamorphic rocks (e.g., gneiss, slate) exhibit anisotropic splitting properties; orientation to foliation is decisive. Sedimentary rocks (e.g., limestone, sandstone) vary widely; porosity and bedding determine the required splitting energy.
Crack control and alignment
Splitting wedges are placed parallel to planned separation planes and – where possible – along existing joints. Relief boreholes prevent uncontrolled crack progression. In areas under preservation or close to sensitive assets, monitoring and small, localized splitting cycles are advisable to observe crack behavior in real time and adjust sequencing.
Hole diameter, depth and spacing
The dimensions depend on the tool, the rock and the target size of the fracture bodies. The diameter must match the splitting cylinder; the depth determines the usable splitting front. Spacing follows the interaction of rock strength, joint density and desired piece size. As a general rule: as few boreholes as possible, as many as necessary – quality over quantity.
Hydraulic power packs and tool integration
Hydraulic power packs provide pressure and flow rate and are the heart of efficient, reliable rock cutting/processing. Correct design prevents energy losses and reduces thermal loads. Short hose runs, suitable couplings, protection against damage and clean oil management increase availability. In combined operations, the same power packs feed different tools in sequence: rock and concrete splitters for the rock, concrete demolition shear for concrete components, hydraulic shear or steel shear for metal components. The interplay of tools reduces changeover times and creates a lean, safe process.
Combination of tools
A practice-oriented sequence releases concrete portions with concrete demolition shear, separates exposed inserts with steel shear or hydraulic shear, and then breaks the rock with rock and concrete splitters. Each tool thus remains in its optimal operating range, wear is minimized and result predictability increases.
Procedure: workflow in rock cutting/processing
- Survey and measurement: record geology, map joints and water flow, define boundary conditions (vibrations, noise, dust).
- Drilling and splitting concept: define hole diameter, depth and grid, set wedge orientation, plan relief boreholes.
- Set up the hydraulic power packs: check pressure and flow rate, secure hose runs, implement leakage and temperature control.
- Drilling: ensure accuracy, hole cleaning and documentation; use flushing or extraction technology if needed.
- Splitting: place splitting cylinders, ramp up pressure in steps, observe crack progression and adjust sequencing.
- Secondary crushing and sizing: release protrusions, rework edges, achieve the desired piece size.
- Material handling and haulage: sort, secure, load; consider routing and load cases.
- Control and documentation: verify dimensional accuracy, edge quality, emission values and stability, and use findings for subsequent cycles.
In transition areas between concrete and rock, the sequence is extended: first loosen concrete components with concrete demolition shear, separate metal parts, then engage the rock in a targeted way with rock and concrete splitters. This order prevents restraint stresses and uncontrolled cracks.
Quality, tolerances and documentation
Quality is measured by dimensional accuracy, edge and surface quality, crack freedom and compliance with emission limits. In natural stone extraction, crack freedom and block geometry are particularly important; in tunnel construction, adherence to profiles and the stability of remaining slopes are key. Continuous documentation – from drilling pattern through pressure curves to the measurement of vibrations – provides the basis for evidence and optimization.
Occupational safety, emissions and permits
Safety at work has top priority. Personal protective equipment, safe setup of power packs, hose protection, retreat zones and clear communication paths are mandatory. Dust and noise reduction (e.g., by wet drilling and sequenced grids), vibration monitoring and careful handling of heavy fracture bodies are standard. Permits and local regulations must be checked for each project; the notes here are general in nature and do not replace an individual assessment. Non-explosive rock removal supports compliance with strict requirements but does not replace a thorough hazard analysis.
Common mistakes and practical tips
- Unsuitable drilling pattern: without reference to joints and bedding, the splitting energy demand rises and crack control diminishes.
- Insufficient hole cleaning: residues in the borehole increase friction and reduce the effectiveness of splitting wedges.
- Overly rapid pressure increments: increasing load too quickly can cause unwanted cracks outside the target area.
- Missing emissions plan: without dust protection, noise control and vibration management, delays and limit exceedances are likely.
- Undersized hydraulic power packs: unsuitable parameters prolong cycles and increase thermal load.
- Neglected interfaces: concrete–rock transitions require a clear sequence with concrete demolition shear followed by splitting techniques.
Terminology and interfaces
Rock cutting/processing focuses on natural rock, whereas concrete demolition addresses components made of concrete. In practice, both areas often overlap: concrete demolition shear prepare deconstruction at building edges, foundations or linings, while rock and concrete splitters loosen in-situ rock with low vibration levels. This clear division of tasks ensures safety, quality and predictability – from rock excavation and tunnel construction to natural stone extraction and special applications with special requirements.