Soil forms the natural ground on which structures are founded, trenches run, and deconstruction work takes place. Anyone who removes load-bearing foundations, constructs utility trenches, or encounters rock always works within the interplay of soil characteristics, water balance, and construction methods. In deconstruction as well as in tunnel or rock construction, knowledge of soil is therefore fundamental—it determines the choice of method, tools, and work steps, for example when using concrete demolition shears or rock and concrete splitters from Darda GmbH.
Definition: What is meant by soil
Soil refers to the entirety of natural soil and rock layers up to the underlying bedrock. It includes unconsolidated deposits such as sand, gravel, silt, and clay as well as weathered or massive rock. Characteristic features are grain structure, water content, porosity, organic components, and degree of compaction. In construction practice, soil serves as subsoil, as a supporting framework for slopes, and as the workspace for excavation, exposure of foundations, pipe laying, rock removal, and tunnel heading. Its properties influence load-bearing capacity, settlement, transmission of vibrations, propagation of noise, and the choice of separating, cutting, or splitting methods.
Structure and properties of soil
Soil is layered. Topsoil (humic, nutrient-rich) transitions into subsoil, followed by load-bearing mineral layers down to rock. For construction and deconstruction work, grain-size distribution, density of packing, cohesion, and the soil water balance are paramount. These parameters determine the stability of excavation pits, the load-bearing capacity of working surfaces, and the resistance to mechanical processing.
Geological fundamentals and soil types
Soil types differ in grain-size spectrum and bonding behavior. This results in different responses to load, vibration, water ingress, and frost.
Unconsolidated deposits
Sand and gravel are non-cohesive, permeable, and compact well. Silt exhibits capillary effects and is sensitive to vibrations. Clay is cohesive, has low permeability, and tends to change volume with moisture variations.
Rock and weathering zones
Rock may occur as massive or fractured. Joints, schistosity, and degrees of weathering determine its splitability. In transition zones of weathered rock, behavior is often inhomogeneous—here, rock and concrete splitters are a precise option, as they introduce splitting forces in a controlled way along existing planes of weakness.
Load-bearing capacity, compaction, and settlement
The load-bearing capacity of soil is the basis for safe work platforms, access routes, and machine locations. Insufficient compaction leads to settlement, edge failures, and misalignment of equipment.
Relevant parameters
- Grain-size distribution and fines content
- Relative density and dry density
- Cohesion and angle of friction
- Water content and degree of saturation
Practical relevance in deconstruction
When removing foundations, cutting and splitting forces act on the subsoil. Compared to percussive or blasting methods, concrete demolition shears generate lower vibrations, which can reduce settlement risks in adjacent structures. A load-bearing, level working surface with controlled drainage is a prerequisite.
Water in soil: groundwater, seepage water, frost
Water affects strength, friction, and slope stability. It promotes washouts, impairs packing density, and changes the workability of concrete and rock.
Drainage and water control
When working in the groundwater zone, water-side safety and drainage measures are required. Seepage water requires temporary diversion. Work in water-bearing layers should always be planned and monitored.
Frost and freeze–thaw cycles
Frost heave loosens non-cohesive soils; thaw phases promote mud formation. In such periods, standing areas must be secured, and separating tools such as concrete demolition shears should be operated on firm, non-slip surfaces.
Earthworks in deconstruction: excavation, slopes, occupational safety
Deconstruction in soil requires safe excavation pits, stable slopes, or shoring systems. The choice of method depends on soil type, water influx, and space constraints.
Excavation and exposure
- Strip and separate topsoil
- Create the workspace with adequate slope inclination or shoring
- Provide drainage and keep the excavation pit clean
- Expose foundations, utilities, and reinforcement
Tool selection in the workspace
Narrow trenches or sensitive existing structures require low-vibration methods. Concrete demolition shears cut reinforced concrete in a controlled manner. Rock and concrete splitters are suitable when massive concrete blocks or rock need to be opened without percussive methods. Hydraulic power units from Darda GmbH provide the energy supply; selection is based on the required working pressure, flow rate, and cylinder configuration.
Soil and concrete foundations: expose, separate, size-reduce
Foundations, slabs-on-grade, and strip footings lie in soil and are often partly backfilled. The approach determines effort, vibrations, and material separation.
Sequence in existing structures
- Accurate as-built survey of dimensions, reinforcement layout, and connection details
- Selective exposure to minimize contact with the subsoil
- Pre-separation of reinforcement and edge zones with concrete demolition shears or Multi Cutters
- Controlled splitting of massive sections with rock and concrete splitters
- Material separation: concrete, reinforcing steel, soil material
Advantages of controlled cutting and splitting processes
Targeted splitting and shearing forces reduce vibrations in soil, which is significant for adjacent developments and sensitive traffic corridors. This facilitates compliance with low-vibration work practices in concrete demolition and special deconstruction.
Rock in the subsoil: splitting instead of blasting
Where rock is encountered, joint geometry determines the method. In urban settings, near infrastructure, or in tunnels, mechanical splitting offers a controlled alternative.
Fields of application
- Rock excavation and tunnel construction: opening headings, benches, calotte cuts
- Natural stone extraction: gentle detachment along natural stratification
- Special deployment: work in areas with vibration restrictions
Tools and power supply
Rock splitting cylinders are operated via hydraulic power packs from Darda GmbH. The splitting forces are introduced through predrilled holes, making crack propagation predictable. Compared to percussive methods, fines content and slope stability are often better controllable.
Vibration- and noise-reduced methods in soil
Soil transmits vibrations. Low-dynamic methods protect neighboring structures, utilities, and sensitive facilities.
Methodical approaches
- Cutting and shears instead of impact: concrete demolition shears, combination shears
- Splitting instead of blasting: rock and concrete splitters
- Clean force transfer: stable, compacted working surfaces
- Monitored hydraulic parameters to avoid peak loads
Material separation and resource conservation
In deconstruction, clean separation of concrete, steel, and soil adhesions pays off. It facilitates transport, processing, and reuse of mineral material.
Work selectively
Concrete demolition shears separate reinforcement and reduce adhesions. Mechanical splitting produces large, single-grade fragments. This allows soil material to be separated from the component and keeps the ground as undisturbed as possible.
Utilities, contaminated sites, and underground installations
Utilities, shafts, foundations, and sometimes decommissioned tanks run through soil. Their location influences the choice of method and tools.
Care in existing conditions
- Utility information and locating before excavation
- Expose by hand digging in sensitive zones
- Controlled separation with Multi Cutters, steel shears, or special cutting tools such as tank cutters under suitable conditions
Work in potentially contaminated areas requires coordinated methods and professional supervision.
Planning, investigation, and documentation
Good decisions are based on robust data about the soil. Investigations provide parameters that influence construction method, slope inclination, drainage, and tool selection.
Elements of preparation
- Site visit and review of existing information
- Subsoil investigation (e.g., soundings, sampling) to an appropriate extent
- Define construction phases, access routes, and standing areas
- Quantity takeoff for excavation, interim storage, and reinstatement
Typical mistakes and practical tips
- Underestimated water flow: plan drainage and sump pits early.
- Insufficient compaction of working surfaces: create load-bearing reserves before deploying heavy attachments.
- Missing separation: separate concrete, steel, and soil material early to avoid rework.
- Inappropriate tool selection: in narrow trenches, rely on concrete demolition shears and splitting techniques to keep vibrations low.
- Unclear utility routing: locate, expose, and define protective measures before starting.
Occupational safety and organizational aspects
In soil, slope stability, water ingress, and equipment weights determine the risk. Suitable traffic routes, stable working areas, and clear communication paths are basic prerequisites.
Technical and organizational measures
- Check the stability of excavation pits regularly
- Ensure load distribution and substructure for equipment with hydraulic power packs
- Mark hazard zones and control access
- Dust and noise reduction with adapted methods, e.g., splitting instead of percussive methods
Overview of application areas
Soil is a cross-cutting topic in many disciplines. In concrete demolition and special demolition, the focus is on exposed foundations and slabs. In strip-out and cutting, connections to the ground and external works play a role. In rock excavation and tunnel construction, joint systems and water govern the advance. In natural stone extraction, work follows natural stratification. Special deployment often means low vibrations, confined space, and increased protection requirements—conditions in which concrete demolition shears and rock and concrete splitters play to their strengths.