Din 4020

DIN 4020 defines the requirements for geotechnical investigations for construction purposes and thus forms the basis for a robust subsoil and rock model. For concrete deconstruction, rock excavation, tunnel construction, and natural stone extraction, it provides the data on which procedures are selected, risks are assessed, and equipment classes are deployed appropriately. This particularly concerns low-vibration methods such as hydraulic rock and concrete splitters and force-transmitting tools such as concrete pulverizers, but also supplementary equipment such as hydraulic power packs (hydraulic power units for site operations), combination shears, multi cutters, steel shears, or tank cutters. The standard ensures that subsoil, rock, and groundwater are systematically determined and documented as boundary conditions for demolition and specialist deconstruction.

Definition: What is meant by DIN 4020

DIN 4020 is a standard that governs the planning, execution, and evaluation of geotechnical investigations as well as documentation in the geotechnical report. It specifies the requirements for the investigation program (e.g., exploration methods, in-situ tests, sampling), laboratory testing of soil and rock, and the derivation of a geotechnical model with governing parameters. The standard supports geotechnical categorization and interacts with the European frameworks for geotechnical verification. The aim is a purposeful, economical, and above all safe foundation of data on which the planning, tendering, and execution of construction and deconstruction works are based.

Scope, structure, and key points of DIN 4020

DIN 4020 extends to ground investigations for building and structural works as well as for rock-related measures. It structures the investigation process into phases (preliminary investigation, field investigation, laboratory testing, evaluation, and reporting) and requires a consistent, validated ground model. Essential elements include defining the level of investigation based on the complexity of the structure and the ground conditions, combining indirect and direct methods (e.g., soundings, boreholes, core logging, test pits, hydraulic and mechanical in-situ tests), defined sampling quality, laboratory characterization (classification and strength/deformation parameters), and aggregation into a geotechnical report. This report documents the governing strata, discontinuities, groundwater conditions, and characteristic values, identifies uncertainties, and provides recommendations for planning and execution.

Significance for concrete demolition, specialist deconstruction, and rock works

For concrete demolition and special demolition, DIN 4020 is not a component standard, but it does provide the contextual knowledge: bearing capacity of the subsoil under site traffic and equipment, groundwater inflow into excavations, sensitivity of adjacent structures to vibration and settlement, potential voids or fills. These boundary conditions influence whether crushing methods with concrete pulverizers and concrete crushers for controlled demolition, cutting techniques, or non-blasting alternatives with rock wedge splitter and concrete splitter are suitable. In rock excavation and tunnel construction, rock descriptions guided by DIN 4020 (discontinuities, orientation, spacing, roughness, weathering) are decisive for borehole spacing, splitting technique, support requirements, and the sequence of extraction. In natural stone extraction, the discontinuity inventory helps determine block sizes and fracture patterns — a core input for hydraulic splitting. For special demolition in sensitive environments (e.g., facilities with strict vibration limits), compliant investigation helps prioritize low-emission methods.

Relevant parameters from DIN 4020 in the deconstruction context

• Rock parameters: uniaxial compressive strength, indirect tensile strength, crack and joint spacing, RQD, shear parameters along discontinuities, degree of weathering, abrasivity.
• Subsoil: relative density, consistency, settlement and bearing capacity parameters, groundwater level and fluctuations, permeability.
• Hydrogeology: inflow rates, piezometric head, potential artesian conditions, influence on drilling and splitting works.
• Context parameters: sensitivity to vibration, neighboring structures, existing utilities, existing support systems.

From ground investigation to equipment selection

The derivation of methods and equipment classes follows from the geotechnical model. The standard ensures that parameters are robust and assumptions are transparent. From this, the operational limits and advantages of individual methods can be derived:

• Massive, sparsely jointed rock: pre-drilling and use of rock wedge splitter and concrete splitter or rock wedge splitters with adapted borehole patterns. Advantageous under strict vibration limits.
• Heavily jointed rock with low tensile strength: larger splitting spacing is possible; complement with mechanical fragmentation where needed.
• Concrete foundations with high reinforcement ratio: concrete pulverizers for selective biting and exposing reinforcement; for massive blocks, combine with splitting to pre-loosen.
• Interior demolition and strip-out: prioritize low-noise, low-vibration processes; hydraulic power packs must be considered regarding required power, hose lengths, and setup based on subsoil bearing capacity.
• Tunnels, adits, caverns: geometry, overburden, and water inflow determine the splitting strategy; safe sequence of exposure, support, splitting, and crushing.
• Industrial deconstruction with steel components: combination shears, multi cutters, steel shears, and tank cutters complement concrete and rock processing; ground data govern crane and work platform loads.

Work preparation according to DIN 4020: investigation, borehole planning, and splitting concepts

Reliable work preparation links the geotechnical model with practical measures. DIN 4020 yields methodological steps applied in deconstruction and rock works:

1. Review preliminary data and records: site plans, as-built documentation, previous boreholes, indications of fills or disturbances.
2. Define field investigations: a combination of boreholes and soundings; in rock, core drilling with systematic discontinuity logging.
3. Laboratory testing: classification and relevant strength/deformation parameters on representative samples; validate against in-situ observations.
4. Build the geotechnical model: stratigraphy, joint system, groundwater; identify uncertainties.
5. Derive the borehole and splitting concept: drilling diameter, depth, spacing, load paths, and splitting direction depending on joint orientation and component geometry.
6. Select equipment and power packs: required hydraulic power, tool geometry, jaw opening, shear force, and hose routing tailored to the site layout.
7. Emissions management: measures to limit vibration, noise, and dust; dewatering for groundwater inflow.
8. Trial area/mock-up: small-scale test to verify assumptions; adjust parameters before area-wide implementation.

Interfaces with European geotechnical regulations

In practice, DIN 4020 is combined with European geotechnical verifications. Relevant aspects include geotechnical categorization, scope of investigation, and quality assurance of parameters. For deconstruction concepts, this means that the ultimate limit state and serviceability of temporary conditions (e.g., demolition stages, work platforms, laydown areas) are based on a recognized foundation of investigation and assessment. Statements in standards do not replace project-specific design; however, they provide a reliable framework for procedures and safety levels.

Documentation: geotechnical report as a working basis

The geotechnical report is the central document in DIN 4020. For the selection of concrete pulverizers, rock wedge splitter and concrete splitter, and complementary tools, the following contents are particularly relevant in practice:

• Stratigraphic log and rock description with discontinuity inventory: decisive for splitting direction, drilling pattern, and extraction sizes.
• Groundwater conditions: influence on drilling methods, dewatering, and corrosion protection for equipment.
• Ground parameters under temporary loads: design of work platforms, admissibility of machine loads and power packs.
• Notes on contaminated sites, fills, and voids: adapt the investigation and deconstruction sequence to minimize risk.
• Recommendations for supplementary investigation: updates in case of deviations during execution.

Risks, environment, and safety in the light of DIN 4020

The standard promotes a systematic understanding of risk. For demolition and rock works, these include in particular: undetected voids, water inflows, unstable slopes, loosened zones, settlement-sensitive neighboring structures, and varying strengths. Methods with hydraulic splitting or mechanical fragmentation are often advantageous in sensitive environments because they work in a targeted manner and with limited vibrations. Regardless of the method, appropriate protective and safety measures apply, e.g., shoring and catch/protection systems, dust and water management, as well as coordinated monitoring (vibrations, settlements, groundwater). Legal frameworks and official requirements must be checked on a project-specific basis.

Focus areas of application

Rock excavation and tunnel construction

The rock description embedded in DIN 4020 provides the basis for exploiting or creating splitting planes. In closely jointed, weathered rock, rock wedge splitters can be used with moderate borehole spacing; in massive rock, tighter patterns and higher splitting forces are appropriate. In tunnel and adit construction, groundwater and overburden influence the sequence of exposure, support, and splitting. Mechanical fragmentation with suitable tools complements detachment at the tunnel face and crown without introducing unnecessary vibrations.

Concrete demolition and gutting works

The selection of concrete pulverizers is based on component thickness, reinforcement ratio, and accessibility. DIN 4020 provides the boundary conditions of the work environment: temporary bearing capacity of the subsoil for equipment and hydraulic power packs, constraints due to neighboring buildings, utilities, and water. In massive components, rock wedge splitter and concrete splitter can contribute to pre-loosening so that pulverizers, multi cutters, or combination shears can intervene in a targeted manner. In interior areas, low-emission working methods gain importance; the investigation supports the planning of load paths and cutting sequences.

Natural stone extraction

For the extraction of natural stone blocks, the orientation of discontinuities is decisive. Mapping in the outcrop guided by DIN 4020 and core logging define block dimensions, splitting directions, and drilling patterns. Hydraulic splitting can be performed along favorable joint orientations with low energy input, which can improve block quality. With varying degrees of weathering, drilling and splitting parameters must be continuously validated.

Special operations

In plant areas with steel and tank components, steel shears, multi cutters, and tank cutters are used in addition to concrete and rock tools. DIN 4020 helps to size work areas and access routes for adequate bearing capacity, limit settlements, and control water inflows. In sensitive neighborhoods, low-vibration methods are prioritized; splitting and cutting sequences are adapted to the geotechnical boundary conditions.

Practice-oriented planning aids from DIN 4020

• Adjust investigation depth and density to the structure’s dimensions and ground variability; clearly state uncertainties.
• Record rock geometry (joint sets) early; align splitting direction and drilling pattern accordingly.
• Make groundwater management an integral component: coordinate drilling methods, dewatering, and work safety with it.
• Design work platforms and intermediate storage areas structurally and geotechnically; set up hydraulic power packs with stable and safe operation.
• Plan equipment combinations proactively: concrete pulverizers for selective removal, rock wedge splitter and concrete splitter for low-vibration pre-loosening, shears and cutters for metallic inserts.
• Establish monitoring to verify assumptions and adapt parameters.

Quality assurance and adaptation during execution

DIN 4020 requires ongoing validation of investigation results. Applied to deconstruction and rock works, this means that observations during execution (drilling progress, water inflow, fracture patterns, tool wear) are systematically documented and compared with the geotechnical model. Deviations lead to an adjusted selection of drill diameters, splitting spacing, pulverizer sequences, or shear strategies. The result is a robust, data-driven process that increases safety, predictability, and technical quality.