Hazard analysis

The hazard analysis is the foundation for safe, plannable, and resource-efficient work in concrete demolition, rock excavation and tunnel construction, in building gutting, as well as in special demolition. It systematically evaluates risks that can arise during separation, cutting, and splitting operations with hydraulic tools. In combination with tools and systems from Darda GmbH – such as concrete demolition shears, rock and concrete splitters, hydraulic power packs, combination shears, Multi Cutters, steel shears, and tank cutters – a forward-looking hazard analysis establishes clear courses of action: for the protection of people, structures, and the environment, as well as for controlled, low-vibration deconstruction and natural stone extraction. Integrated into method statements and risk assessments (often framed as RAMS or JSA/JHA), it provides a traceable basis for decision-making across planning and execution.

Definition: What is meant by a hazard analysis?

Hazard analysis is the systematic identification, evaluation, and control of hazards that can occur during an activity, a work method, or at a workplace. It is closely linked to risk assessment and forms the methodological core of a safety concept. In demolition and rock applications, it includes technical, organizational, and person-related risks, for example from hydraulic pressure, residual energy in components, fall and drag motions, media releases, noise, dust, vibrations, or uncontrolled separation progress. The hazard analysis is object- and task-specific, begins in the planning phase, and accompanies the project through execution, control, and documentation. Legal requirements and rules of the art can vary by country and project; they should always be considered in general and interpreted project-specifically. Clear differentiation between hazard (source of potential harm) and risk (combination of probability and severity) enables prioritization according to the ALARP principle and supports transparent residual risk acceptance.

Objectives, benefits, and scope in demolition and rock cutting/processing

Hazard analysis creates transparency about risks, defines protection objectives, and derives effective measures. It increases execution safety in concrete demolition and special deconstruction, in building gutting and cutting, in rock excavation and tunnel construction, in natural stone extraction, and in special demolition. It also strengthens proof of due diligence toward clients, authorities, insurers, and stakeholders.

• Protection of personnel: Prevent crushing, cutting, impact, and fall accidents as well as exposure to noise, dust, and hazardous substances.
• Component and process safety: Avoid uncontrolled fractures, spalling, edge break-offs, swing and fall motions, and hydraulic leaks.
• Environmental protection: Limit vibrations, dust, media releases, and secondary damage to adjacent structures.
• Planning and schedule reliability: Reduce downtime through clear procedures, interface management, and effective emergency plans.
• Quality of results: Enable controlled separations with predictable geometry, minimize rework, and safeguard neighboring assets.

Process and methodology of hazard analysis

The methodology follows a structured sequence and can be applied to all relevant tools and methods, such as concrete demolition shears, rock and concrete splitters, combination shears, steel shears, tank cutters, or Multi Cutters. Where practical, it is aligned with the method statement and permits-to-work for consistent implementation on site.

1. Clarify the work order: Objective, limits, component function, load-bearing behavior, utility runs, boundary conditions (weather, height, interior).
2. Gather information: Drawings, as-built data, utility line and reinforcement layouts, material properties, access, load transfer.
3. Identify hazards: Mechanical, hydraulic, electrical, chemical, thermal, ergonomic, environmental/context.
4. Assess risks: Probability of occurrence and severity of harm; prioritize by risk.
5. Define measures: According to the STOP principle: substitution, technical, organizational, personal measures.
6. Plan execution: Responsibilities, communication channels, exclusion and rescue routes, safety distances, monitoring.
7. Verify effectiveness: On-site check, adapt to changing conditions, documentation.
8. Close the loop: Capture lessons learned, update standard procedures, and feed improvements into future planning.

Typical hazards and risk scenarios

The following hazard areas occur frequently in these applications and should be considered in a differentiated manner in every hazard analysis. In addition, interface risks at transitions between methods and trades warrant special attention.

• Structural system and component failure: Unexpected load redistributions, bond and restraint forces, hidden pre-damage.
• Uncontrolled fracture propagation: Crack wrap-around, spalling, rockfall; especially in rock excavation and with high reinforcement ratios.
• Hydraulic risks: High-pressure leaks, hose bursts, residual pressure, unintended movements of shears or cylinders.
• Media and hazardous substances: Asbestos, PAHs, mineral dust (quartz), coolants/lubricants, tanks with residual contents.
• Noise, dust, vibrations: Effects on personnel, neighbors, sensitive infrastructure.
• Fall and crushing hazards: Work at height, edge areas, swinging components, constrictions.
• Surroundings and third-party influences: Traffic, pedestrians, weather, water ingress in tunnel or rock areas.
• Confined and restricted spaces: Oxygen deficiency, explosive atmospheres, difficult egress in tanks or shafts.

Hazard analysis for concrete demolition shears: specifics and measures

Concrete demolition shears are tools for controlled separation and downsizing of reinforced concrete components. The hazard analysis focuses on the interaction of cutting and pressing forces with the load-bearing behavior of the component and its surroundings. Consider geometry, reinforcement content, and support conditions throughout the sequence.

Key hazards

• Load redistribution: Removing load-bearing webs or compression zones can lead to sudden failure.
• Exposure of reinforcement: Tension slip, sudden bar movements, spring-back.
• Spalling: Fragment ejection at edges and with cold concrete.
• Tool movement: Unintended closing/opening, swiveling under load.

Recommended measures

• Sequence planning: From non-load-bearing to load-bearing areas; temporary shoring; defined residual cross-sections.
• Safety distances: Define drop and swing zones; use shielding against fragment ejection.
• Hydraulic safety: Hose protection, pressure relief before coupling, leakage checks; ensure emergency stop organizationally.
• Reinforcement control: Plan the cutting path, reduce tensile forces (e.g., pre-load, relieve), then selectively cut remaining rebar.
• Communication: Spotter, clear signals, radio discipline; ensure line of sight to the tool.
• Pre-weakening and sizing: Where feasible, perform pre-weakening cuts and size elements for predictable handling and set-down.

Hazard analysis for rock and concrete splitters: specifics and measures

Rock and concrete splitters generate splitting forces in the material and enable low-vibration separations. The analysis focuses on crack steering, edge distances, and the behavior of large components or rock masses. Borehole quality and spacing determine energy input and crack path reliability.

Key hazards

• Crack propagation: Undesired crack path along weakness zones or reinforcement.
• Sudden separation: Abrupt component detachment, rockfall, tipping motions.
• Borehole edge: Breakout at the borehole, wedge jamming, tool kick-back.
• Vibrations and neighboring structures: Crack formation in adjacent components due to uncontrolled force transmission.

Recommended measures

• Crack steering: Choose drilling pattern, center spacings, edge distances, and drilling depth so the crack path is predefined.
• Stepwise splitting: Introduce forces in small increments; intermediate checks; provide shoring or catch systems.
• Tool maintenance: Inspect wedges/cylinders, clean boreholes, minimize friction; safely release residual pressure.
• Securing the surroundings: Keep fall and drag areas clear; keep people away; warnings and barriers.
• Monitoring: Use witness marks or tell-tales to visualize crack initiation and arrest points before proceeding.

Safely mastering hydraulic power packs and energy sources

Hydraulic power units supply tools with pressure and flow. The hazard analysis considers energy isolation, hose routing, and emergency procedures. Robust hose management and spill control are central to preventing secondary damage.

• Energy isolation: Isolate, secure, label; relieve residual pressure in a defined manner.
• Hose management: Kink and abrasion protection, avoid trip hazards, correctly lock couplings.
• Leak and fire risk: Drip mats, containment systems, suitable extinguishing agents; keep ignition sources away.
• Operator position: Safe standing position, protection from recoil/swing, clear view of the work area.
• Start-up and shutdown discipline: Use defined checklists, verify pressure settings and emergency stop function before engaging tools.

Application areas in focus: risk-based priorities

Concrete demolition and special deconstruction

• Structural analysis: Identify load paths; interaction of concrete demolition shears with the remaining load-bearing structure; plan temporary systems.
• Interfaces: Combination with combination shears, steel shears, or Multi Cutters in concert; control demolition sequencing.
• Verification: Instrument simple deflection or crack gauges where consequences of failure are high and adjust steps accordingly.

Building gutting and cutting

• Indoor conditions: Ventilation, dust suppression, noise reduction measures; locate and secure utility lines.
• Component tie-ins: Release attachments, check cavities; controlled set-down of sections.
• Logistics in tight spaces: One-way routes, traffic marshals, and clean handover zones for debris removal.

Rock excavation and tunnel construction

• Geology: Joints, bedding, water ingress; apply splitters so natural weaknesses are used, not activated uncontrollably.
• Structural stability: Plan post-stabilization (anchors, shotcrete); rockfall nets and exclusion zones.
• Water management: Drainage paths, silt control, and safe pumping arrangements to avoid erosion and undermining.

Natural stone extraction

• Quality cut: Crack steering for clean blocks; minimize vibrations; select equipment according to rock tensile strength.
• Logistics: Haul routes, tipping edges, loading movements within the safety distance.
• Traceability: Document block origin, orientation, and handling to maintain quality and reduce damage rates.

Special demolition

• Residual risks: Unknown media, contaminated areas, release of pollutants; stepwise reconnaissance and permits.
• Tank cutting: Inerting, degassing, keep ignition sources away; cutting direction and containment concepts.
• Compatibility: Verify tool materials and seals with potential contaminants to prevent degradation and leaks.

Controlling noise, dust, vibrations, and media releases

These cross-cutting topics affect almost all methods and tools. Early coordination with neighbors and operators of sensitive assets supports predictable site conditions and avoids stoppages.

• Noise: Limit exposure times, prioritize low-noise methods, shielding and personal protective equipment.
• Dust: Wet methods, extraction, binding agents; pre-process materials; clearance measurements in sensitive areas.
• Vibrations: Monitoring with limit values; favor methods with low dynamic excitation, e.g., splitting techniques.
• Media: Locate lines, drain, depressurize; provide containment and sealing systems.
• Water and sludge: Manage slurry, prevent run-off, and install sediment control where wet methods are used.

STOP principle: systematics of measures

The order of measures is central to effectiveness. Applying the hierarchy consistently prevents reliance on personal protective equipment as the primary control and strengthens the overall safety concept.

1. Substitution: Choose methods that fundamentally reduce risks (e.g., low-vibration splitting techniques instead of percussive methods where possible).
2. Technical: Protective devices, catch systems, pressure limits, shielding, shoring, defined anchorage points.
3. Organizational: Work plans, exclusion zones, spotters, permits/releases, shift handover communication, weather and surroundings monitoring.
4. Personal: Suitable protective clothing, hearing and respiratory protection, cut protection, fall protection; appropriate tool certification/qualification.

Securing surroundings, structural control, and emergency management

• Exclusion and warning zones: Mark visibly, monitor access, provide alternative routes.
• Structural monitoring: Cracks, deformations, noises; use gauge marks or simple control means.
• Load handling: Anticipate hoists, slings, and bearing zones; limit swing and drop motions.
• Emergency plans: Escape routes, first aid, pressure relief, energy stop; regular drills.
• Stop-work authority: Define clear thresholds and empower all roles to halt operations if conditions change.

Documentation, instruction, and effectiveness control

Traceable documentation increases safety and supports quality assurance. Visual evidence and concise checklists help verify implementation and enable rapid learning cycles.

• In advance: Check boundary conditions, releases/permits, condition of equipment and tools, qualifications.
• Ongoing: Adjust to changing conditions, short and safety briefings, visual inspections.
• Close-out: Effectiveness review of measures, residual hazards, handover and cleanliness state.
• Instruction: Device-specific briefing, e.g., concrete demolition shears, rock and concrete splitters, and hydraulic power packs; clear responsibilities.
• Evidence: Photo logs, monitoring records, and sign-offs to demonstrate that controls performed as intended.

Practice-oriented checklist for hazard analysis

• Order and objective defined? Load paths and boundary conditions known?
• Components and rock examined (reinforcement, joints, media/utilities)?
• Tool selection justified (concrete demolition shear, splitter, shear, tank cutter)?
• Hydraulic power packs checked, hoses and couplings intact, residual-pressure concept in place?
• Splitting or cutting sequence defined, shoring planned, catch systems prepared?
• Exclusion zones set up, spotters designated, communication secured?
• Dust, noise, and vibration measures defined and monitored?
• Disposal and logistics chain (laydown, haulage, tipping edges) safe?
• Emergency and rescue concept aligned, first aid available?
• Documentation and permits up to date, instruction carried out?
• Monitoring and measuring devices available and calibrated (e.g., vibration, dust)?
• Interfaces with adjacent trades coordinated, handovers and isolations confirmed?
• Contingencies defined for weather, power loss, tool failure, and unexpected findings?