The deep cut is a core method for controlled separation and removal of concrete, reinforced concrete, and rock. It is used to establish a defined separation plane at significant depth—for example to segment massive components, to guide cracks in rock, or to prepare for subsequent splitting and gripping. In practice, the deep cut is often combined with concrete pulverizers, stone and concrete splitters (e.g., hydraulic rock and concrete splitters), hydraulic power packs, as well as supplementary cutting and shearing tools. This enables precise, low-vibration, and material-appropriate results in the application areas of concrete demolition and special demolition, gutting works and cutting, rock excavation and tunnel construction, natural stone extraction, and special operations.
Definition: What is meant by deep cut
The term deep cut refers to a deep, linear separation cut or deep-reaching kerf in mineral construction materials and natural stone that facilitates subsequent detachment, load redistribution, or controlled breakage. The deep cut differs from a near-surface saw cut by its greater cutting depth relative to the component thickness and by its function as a controlling separation plane. It can be created using sawing methods (e.g., wall, wire, or floor saw) or—especially in rock and massive concrete bodies—in combination with drilling arrays and hydraulic splitting. Typical objectives are:
- Stress relief and crack guidance to avoid uncontrolled fractures
- Separating and lowering heavy segments in special demolition and gutting works
- Preparation for the wedge or spreading method with stone and concrete splitters
- Clean cut edges for subsequent gripping, breaking, or pulverizer work (e.g., with concrete pulverizers)
Methods and procedures for deep cut operations
In practice, several procedures have become established that are used individually or in combination depending on material, component geometry, and boundary conditions. Common are:
- Sawing methods with high cutting depth (wall saw, floor saw, wire saw) for long, straight separation planes in reinforced and mass concrete.
- Drilling and splitting methods: drilling arrays define depth and geometry, then stone and concrete splitters generate guided crack propagation along the planned plane.
- Combined approach: pre-separation cuts (relief cuts) and core drilling for crack guidance, followed by splitting and controlled lifting with concrete pulverizers or grappling tools.
- Cutting reinforcement and embedded inserts using multi cutters, steel shears or—on complex steel assemblies—additional shearing and cutting tools.
The power supply for the hydraulic components is provided by hydraulic power packs. This makes it possible to generate high splitting forces in the material without resorting to blasting methods. The result is low-vibration and blast-free workflows with reproducible cut quality.
Applications and objectives
The deep cut is used in various fields of work and adapted to the specific conditions:
- Concrete demolition and special demolition: segmenting massive foundation blocks, creating separation joints in parapets, walls, or slabs, setting down components for craning out. After the deep cut, concrete pulverizers facilitate gripping, rotating, and controlled breaking.
- Gutting works and cutting: selective deconstruction in existing structures, e.g., openings in load-bearing members, detaching stair flights or shafts. Deep cuts serve as a defined cutting guide for subsequent cutting and pulverizer operations.
- Rock excavation and tunnel construction: crack guidance in compact rock, establishing separation planes parallel to bedding, preparing breakouts. Here, drilling arrays are often combined with stone and concrete splitters.
- Natural stone extraction: winning raw blocks along natural joint systems, minimizing offset and overbreak. Deep cuts promote smooth separation faces and material-appropriate block formats.
- Special operations: work in sensitive areas with stringent vibration and noise requirements, e.g., in facilities, hospitals, or heritage structures. The combination of deep cut, hydraulic splitting, and low-noise pulverizer work helps protect the surroundings.
Planning and structural constraints
A deep cut affects the structural safety and serviceability of components. Before starting, load paths, temporary shoring, and cut direction must be planned. Coordination with qualified specialist planners and adherence to recognized rules and local requirements is generally recommended. Key parameters include:
- Cutting depth and kerf width in relation to component thickness
- Edge distances to corners, openings, and embedded inserts
- Reinforcement layout, prestressing tendons, services, and utilities
- Component dimensions and permissible segment weights for removal
- Temporary support, lowering, and crane pick points
Geometry and cut guidance
The cut path follows the planned separation plane: straight runs reduce notch stresses; corners are often relieved with core drilling to prevent breakout. In rock, bedding and joint systems govern the approach; the cut line should support crack propagation and block geometry.
Drilling patterns and preparations
For drilling-and-splitting methods, the drilling pattern defines the subsequent crack path. Uniform hole spacing and diameters matching the deployed stone and concrete splitters are common. In reinforced concrete, reinforcement is locally exposed before splitting or cut later with shears. Dry or wet drilling is selected based on dust and water management, material, and working environment.
Equipment combinations in deep cut operations
The methodological added value arises from a coordinated combination of tools:
- Stone and concrete splitters: generate defined crack progression along the deep cut or a drilling array, especially in mass concrete and rock.
- Concrete pulverizers: grip, hold, and enable controlled breaking or setting down of separated segments along the prepared plane.
- Hydraulic power packs: power supply and pressure control for splitting and pulverizer tools; important for consistent output.
- Combi shears and multi cutters: cutting reinforcing steel, sections, and embedded components once the deep cut has already separated the concrete.
- Steel shears: for heavy reinforcement, beams, or anchors exposed after the deep cut.
- Tank cutters: for special cases where components are connected to vessels, cladding sheets, or tank structures and steel plates must be cut safely.
Workflow: step by step
- Survey and assessment: materials, reinforcement, embedded items, joint systems, access, emission requirements.
- Surveying and marking: separation plane, edge distances, drilling fields, engagement points for pulverizers and lifting gear.
- Preparations: shoring, protective walls, water and dust management, removal of loose parts.
- Creating the deep cut: sawing to the defined depth or laying out drilling arrays for depth and alignment.
- Splitting and relieving: inserting the stone and concrete splitters for crack guidance and segmentation.
- Cutting reinforcement: using multi cutters or steel shears on exposed bars and sections.
- Gripping and setting down: using concrete pulverizers or lifting gear, controlled release, and removal.
- Finishing: re-trimming edges, sealing drill holes, dressing the surface.
- Documentation: dimensions, cutting depth, deviations, photo documentation, and release.
Safety, environment, and emissions
Deep cutting generates local impacts from noise, dust, water, vibration, and potential falling segments. Protective measures are selected project-specifically and should follow recognized rules of practice and applicable requirements without judging the individual case. Key points include:
- Personal protective equipment, safe working platforms, barricading, and crane/rigging inspection
- Determination of segment weight, load distribution, and redundancy during lifting
- Dust and water management (wet cutting, extraction, filtration), orderly disposal
- Low-vibration approach through a combination of deep cut, splitting, and pulverizer work
- Electrical and media clearances (cables, voids, pressure lines), clearance testing on hollow bodies
Quality assurance and documentation
The quality of a deep cut is evidenced by straight cut edges, reproducible depth, and controlled crack guidance. Proven practices include reference measurements (cutting depth, plumbness, squareness), trial areas, markings, and interim inspections. In reinforced concrete, targeted exposure of reinforcement improves subsequent work with shears and pulverizers. Traceable documentation supports proof obligations and coordination with follow-on trades.
Typical errors and how to avoid them
- Insufficient cutting depth: leads to uncontrolled break edges. Remedy: depth measurements and incremental follow-up cuts.
- Missing relief cuts at corners: promotes breakout. Remedy: core drilling or radius detailing.
- Inappropriate drilling pattern: crack deviates from the plane. Remedy: constant spacing with diameters matching the material and splitter.
- Reinforcement not considered: hinders separation. Remedy: locating, exposing, and targeted cutting.
- Insufficient shoring: settlement or binding. Remedy: temporary safeguards and controlled load redistribution.
- Excessive splitting force without a pre-separation cut: unwanted overbreak. Remedy: combined procedure using deep cut and moderate splitting.
Material and rock specifics
Reinforced concrete requires a considered separation of the concrete matrix and reinforcement. Mass concrete without reinforcement can be split particularly well along a deep cut. In natural stone, joint spacing, grain fabric, and moisture influence crack propagation. In metamorphic or strongly bedded rock, the cut and splitting directions should run with the structure to achieve smooth separation faces and economical block sizes.
Post-treatment of cut surfaces
The required roughness, flatness, and edge detailing are determined by the follow-on trade: for bonded joints, a roughened surface can be advantageous; for exposed surfaces, a more uniform cut is preferable. Exposed reinforcement must be protected against corrosion. Drill holes are filled as needed; chamfers on sharp edges increase durability.
Practical examples
During deconstruction of a massive machine foundation, a circumferential deep cut allows the component to be set down in manageable segments. After the saw cut, stone and concrete splitters are used to open the separation plane; the segments are guided and removed with concrete pulverizers. In rock removal, a grid of deep boreholes establishes the desired separation plane; hydraulic splitting then guides the crack path until the block is extracted. In gutting works, a vertical deep cut with subsequent reinforcement cutting creates the conditions to release a wall section in a controlled manner without affecting adjacent components.