Plant reactions, debris and removal of supports change the load path together. Stop for new cracking or movement and obtain the responsible engineer decision before entering or moving debris in an unstable area.
AI-generated reference material. It has not been verified or approved by a professional. Before use, a qualified person must review and adapt it to applicable Singapore requirements, the actual equipment and site, and approved safe work procedures.
1. Singapore legal and technical basis
Singapore demolition requires the applicable BCA/QP planning, structural appraisal and permit arrangements before work. BCA guidance highlights the condition of the actual structure, protection of adjoining areas and stability as debris accumulates. WSH controls for machinery, dust, noise and hazardous materials apply independently of the demolition sequence.
| Source category | Task application and limit |
|---|---|
| MOM - Risk management | Assess changing structural, plant and public interfaces. Official explanation of WSH Risk Management duties, not a complete consolidated statutory text. |
| BCA - Enhanced requirements for safety of demolition works, 1 September 2022 | Resolve structural appraisal, residual stability and public protection. Direct URL redirected to circulars index; indexed selected text only. Applicable-building definition and complete submission package not reviewed; QP must confirm current scope and requirements. |
| BCA - Permit for structural works | Confirm applicable permit and material-change approval. Actual work classification, exemptions and submitted design were not supplied. Linked forms were not reviewed and are not reproduced as completed records. |
| MOM - Duties in asbestos-related work | Resolve survey and separate approved asbestos removal before disturbance. Main duty summary only; actual survey, removal method, notifications, clearance and waste records not provided. This JSA does not authorise asbestos disturbance. |
| MOM - Requirements for hygiene monitoring | Assess concrete dust and actual occupational exposure. Material-specific exposure and actual monitoring frequency have not been determined. No workplace measurement is supplied. |
| MOM - Hearing Conservation Programme | Apply actual noise assessment and hearing conservation. General programme explanation. Actual exposure, monitoring and reporting duties need the workplace assessment; no noise reading or universal tool-use duration is supplied. |
Use Singapore requirements and SI units. Manufacturer limits apply to the actual model. Foreign technical examples do not establish Singapore statutory duties. A job safety analysis or completed checklist is not a permit or approval.
2. Scope and required inputs
Included scope
Planning, preparation, execution, controlled shutdown and handover are covered by the eight stages below. Each stage requires site-specific inputs and competent review.
Separate review
Explosive demolition, deliberate collapse, unplanned cutting of prestressing tendons and entry into unstable remnants are excluded.
| Required input | What to verify |
|---|---|
| Survey and plan | Survey and drawings · Stage load checks · Support design · Engineer release |
| Isolate services | Isolation certificates · Service markings · Material survey · Void investigation |
| Check machine | Machine and breaker IDs · Coupler test record · Hose defect status · Protection suitability |
| Position and exclude | Bearing assessment · Traffic plan · Zone boundaries · Signal test |
| Break in sequence | Current stage drawing · No people in zone · Support condition · Stage hold point |
| Monitor exposure | Dust-control function · Exposure assessment · Crack and movement log · Site trigger levels |
| Remove debris | Debris load tally · Truck loading plan · Route clearance · Waste classification |
| Stop and hand over | Isolation verification · Residual-stability record · Equipment defects · Next-stage release |
Select head, eye, hand and foot protection for the actual hazards and compatibility. Respiratory, hearing, electrical and fall protection require task-specific selection and training; equipment must not create an additional hazard. PPE does not replace isolation, structural stability or exclusion.
Singapore application
The QP must match the demolition plan to the actual building and determine the required submission, permit and supervision. Confirm plant, breaker reactions, debris limits and support through lower levels for every stage. This scope excludes explosive demolition, deliberate collapse and unplanned prestressing-tendon cutting.
3. Eight-stage JSA
| Job stage | Hazards and effects | Failure factors | Controls | Site verification | P | S | R | A |
|---|---|---|---|---|---|---|---|---|
| 1. Survey and plan | 1. Progressive collapse2. Weak suspended slab3. Adjacent damage4. Prestress release | 1. Load path unknown2. Plant loads omitted3. Shoring removed4. Tendons unlocated | 1. Engineer staged sequence2. Assess plant and debris loads3. Design support through floors4. Special plan for prestress | 1. Survey and drawings2. Stage load checks3. Support design4. QP demolition-stage release | ||||
| 2. Isolate services | 1. Electrocution2. Gas explosion3. Asbestos fibres4. Hidden void collapse | 1. Plans taken as proof2. Live services cut3. No hazardous-material survey4. Scan used alone | 1. Verify services in field2. Isolate with owners3. Survey and abate materials4. Confirm voids by safe checks | 1. Isolation certificates2. Service markings3. Material survey4. Void investigation | ||||
| 3. Check machine | 1. Attachment falls2. Hydraulic injection3. Cab penetration4. Uncontrolled movement | 1. Coupler not locked2. Hose pinhole leak3. Wrong protection4. Incompatible breaker | 1. Follow model instructions2. Verify coupler engagement3. Inspect without hand leak test4. Check cab and safety devices | 1. Machine and breaker IDs2. Coupler test record3. Hose defect status4. Protection suitability | ||||
| 4. Position and exclude | 1. Machine overturns2. Crushing in swing3. Debris strikes public4. Edge collapse | 1. Weak operating bench2. Spotter enters radius3. Barrier too close4. Escape route blocked | 1. Approve machine position2. Separate people and plant3. Size zone for collapse/debris4. Keep withdrawal route clear | 1. Bearing assessment2. Traffic plan3. Zone boundaries4. Signal test | ||||
| 5. Break in sequence | 1. Unplanned collapse2. Flying fragments3. Falling wall4. Loss of stability | 1. Undercut support2. Excessive bite3. Work below unstable mass4. Plan bypassed | 1. Follow approved stages2. Use suitable shielding3. Keep cab outside danger4. Stop before changing sequence | 1. Current stage drawing2. No people in zone3. Support condition4. Stage hold point | ||||
| 6. Monitor exposure | 1. Silica inhalation2. Hearing damage3. Vibration effects4. Adjacent instability | 1. Water fails2. Cab seal leaks3. Alarm ignored4. Dust masks assumed enough | 1. Suppress dust at source2. Maintain suitable cab filtration3. Assess noise and respiration4. Stop at instability or limits | 1. Dust-control function2. Exposure assessment3. Crack and movement log4. Site trigger levels | ||||
| 7. Remove debris | 1. Floor overload2. Falling rubble3. Truck strike4. Sharp reinforcement | 1. Unplanned stockpile2. Oversize bucket load3. Person under bucket4. Cutting stressed bars | 1. Control pile loads2. Load in segregated area3. Keep clear of bucket path4. Plan bar cutting separately | 1. Debris load tally2. Truck loading plan3. Route clearance4. Waste classification | ||||
| 8. Stop and hand over | 1. Residual pressure2. Attachment drops3. Unstable remnant4. Unauthorised restart | 1. Raised tool left2. Accumulator still charged3. Defect unreported4. Access reopened | 1. Lower and secure attachment2. Isolate per manufacturer3. Secure remaining structure4. Record defects and handover | 1. Isolation verification2. Residual-stability record3. Equipment defects4. QP next-stage limits |
P/S/R/A and actual measurements, checks, names and signatures remain blank for the site assessment. A score cannot waive a required control.
4. Hypothetical scenario and failure mechanisms
Retained educational illustration; not evidence of an actual incident.
The scenario and record comparisons are fictional teaching examples, not records of real incidents, measurements, inspections, signatures or approvals.
| Item | Fictional scenario |
|---|---|
| Initial situation | An excavator is proposed for an upper-floor demolition stage. |
| Changed condition | Supports are omitted and debris accumulates beyond the planned area. |
| Failure path | The changing load path can overload the slab or supporting levels. |
| Possible outcome | A local failure could propagate and endanger the machine and people below; this is a hypothetical sequence. |
| Prevention barrier | Suspend work until stage loads, support installation and the exclusion area are rechecked. |
Failure mechanisms
Machine weight, breaker reactions and accumulated debris act together. A slab thickness, ground mat or vibration reading alone cannot demonstrate capacity. Shoring must transfer loads to verified supports through every affected level.
Use the actual carrier, attachment and coupler instructions. Moving hydraulic levers alone may not discharge accumulators; never search for a pressurised leak with a hand. Dust and noise controls require exposure assessment, not a universal respirator rating.
Decision sequence
| Decision stage | What to verify |
|---|---|
| Known facts | An excavator is proposed for an upper-floor demolition stage. |
| Unresolved matters | Supports are omitted and debris accumulates beyond the planned area. |
| Reason to hold | The changing load path can overload the slab or supporting levels. |
| Required evidence | Survey and drawings · Stage load checks · Support design · Engineer release |
| Restart decision | Suspend work until stage loads, support installation and the exclusion area are rechecked. Site evidence is pending; no work permission is granted by this document. |
5. Hold and proceed decisions
| Condition | Action | Evidence | Proceed when |
|---|---|---|---|
| Progressive collapse | Engineer staged sequence · Assess plant and debris loads · Design support through floors · Special plan for prestress | Survey and drawings · Stage load checks · Support design · Engineer release | Stage loads verified |
| Machine overturns | Approve machine position · Separate people and plant · Size zone for collapse/debris · Keep withdrawal route clear | Bearing assessment · Traffic plan · Zone boundaries · Signal test | Danger zone clear |
| Silica inhalation | Suppress dust at source · Maintain suitable cab filtration · Assess noise and respiration · Stop at instability or limits | Dust-control function · Exposure assessment · Crack and movement log · Site trigger levels | Controls functioning |
Similar situations, different decisions
The scenario and record comparisons are fictional teaching examples, not records of real incidents, measurements, inspections, signatures or approvals.
| Comparison | Situation A | Situation B |
|---|---|---|
| Survey and plan | Load path unknown · Plant loads omitted · Shoring removed · Tendons unlocated | Engineer staged sequence · Assess plant and debris loads · Design support through floors · Special plan for prestress |
| Position and exclude | Weak operating bench · Spotter enters radius · Barrier too close · Escape route blocked | Approve machine position · Separate people and plant · Size zone for collapse/debris · Keep withdrawal route clear |
| Monitor exposure | Water fails · Cab seal leaks · Alarm ignored · Dust masks assumed enough | Suppress dust at source · Maintain suitable cab filtration · Assess noise and respiration · Stop at instability or limits |
6. Roles and supervision
| Role | Responsibility |
|---|---|
| Work supervisor | Confirm the work method, resources, competence and stage permission. |
| Technical reviewer | Resolve design, electrical, structural or equipment questions within the person’s competence. |
| Authorised operator / worker | Inspect before use, follow the agreed method and stop when conditions change. |
| Area controller | Keep people outside the danger area and maintain agreed communications. |
| Handover authority | Review open defects, restrictions and evidence before returning the area or starting the next stage. |
Supervision, records, handover
| Job stage | Technical and procedural controls | Site verification |
|---|---|---|
| Plan review | 1. Review current method2. Assign technical owner3. Close critical queries | 1. Survey and drawings2. Reviewer and date3. Open-issue register |
| Competence | 1. Check task competence2. Assign stop authority3. Verify emergency readiness | 1. Training scope2. Briefing record3. Rescue plan |
| Prestart evidence | 1. Inspect actual asset2. Link evidence to stage3. Leave unchecked fields blank | 1. Machine and breaker IDs2. Inspector and time3. Evidence reference |
| Change control | 1. Stop and secure area2. Revise affected controls3. Obtain restart permission | 1. Change reason2. New evidence3. Restart authority |
| Shift handover | 1. Transfer isolation formally2. Assign zone controller3. Explain remaining hazards | 1. Isolation register2. Receiving person3. Restrictions and time |
| Closeout | 1. Quarantine defective items2. Confirm release conditions3. Archive factual records | 1. Defect disposition2. Release decision3. Record revision |
Singapore application
The QP and demolition supervisor control stage limits and residual support. The plant operator stops for changing ground, structure or attachment behaviour. The waste and exposure leads control hazardous-material segregation, removal loads and dust/noise measures; a cab shield cannot compensate for structural instability.
7. Hold points and record quality
| Hold point | Evidence before release | Confirmation / approval |
|---|---|---|
| Start | Planning, preparation, execution, controlled shutdown and handover are covered by the eight stages below. Each stage requires site-specific inputs and competent review. | |
| HP-1 Survey and plan | Survey and drawings · Stage load checks · Support design · Engineer release | |
| HP-2 Position and exclude | Bearing assessment · Traffic plan · Zone boundaries · Signal test | |
| HP-3 Break in sequence | Current stage drawing · No people in zone · Support condition · Stage hold point | |
| HP-4 Stop and hand over | Isolation verification · Residual-stability record · Equipment defects · Next-stage release |
Complete after actual checks. Recheck after changes, defects or shift handover.
Record comparison examples
The scenario and record comparisons are fictional teaching examples, not records of real incidents, measurements, inspections, signatures or approvals.
The boxes are static record prompts, not interactive or saved approvals. A tick does not establish suitability or permission to restart. Record the evidence, person, time and unresolved issues; retain the change history.
| Record type | Insufficient record | Record checklist |
|---|---|---|
| Before start | Not verified or not recorded | □ Location and asset ID□ Verifier and time□ Evidence reference□ Unresolved issues |
| Critical control | Not verified or not recorded | □ Control checked□ Actual observation□ Inspector and time□ Decision authority |
| Change or stop | Not verified or not recorded | □ Change and reason□ Immediate protection□ Revised evidence□ Restart authorisation |
| Handover | Not verified or not recorded | □ Remaining hazards□ Equipment restrictions□ Receiving person and time□ Next inspection |
8. Pre-work checks and emergency response
| Check item | Result | Person / action |
|---|---|---|
| □ Survey and plan: Survey and drawings | ||
| □ Isolate services: Isolation certificates | ||
| □ Check machine: Machine and breaker IDs | ||
| □ Position and exclude: Bearing assessment | ||
| □ Break in sequence: Current stage drawing | ||
| □ Monitor exposure: Dust-control function | ||
| □ Remove debris: Debris load tally | ||
| □ Stop and hand over: Isolation verification | ||
| □ Release / handover authority |
Stop work
Stop if a critical control is missing, the conditions change, an unplanned movement occurs, or an exclusion boundary is breached. Secure the area. The responsible competent person must resolve the cause, document the evidence and obtain site authorisation before restart.
Emergency response
Stop work and warn others from a safe position. Isolate energy only where safe. Activate the site emergency plan and local emergency services. Do not enter an unstable structure, touch an electrically exposed casualty or attempt an improvised suspended rescue. Use trained rescuers and the planned equipment.
9. Sources and review limits
Public-source review: 14 October 2026. Only the material and limits identified below were reviewed.
| Source | Reviewed material | Task application |
|---|---|---|
| MOM - Risk management | Responsibilities; routine and non-routine work; hierarchy of control and risk assessment team. Official explanation of WSH Risk Management duties, not a complete consolidated statutory text. | Assess changing structural, plant and public interfaces. |
| BCA - Enhanced requirements for safety of demolition works, 1 September 2022 | Selected indexed annex text on top-down high-reach work, residual stability/debris, public protection and structural appraisal for other buildings. Direct URL redirected to circulars index; indexed selected text only. Applicable-building definition and complete submission package not reviewed; QP must confirm current scope and requirements. | Resolve structural appraisal, residual stability and public protection. |
| BCA - Permit for structural works | Main overview, joint developer/QP/builder application, material-change approval and immaterial-change records; current page March 2026. Actual work classification, exemptions and submitted design were not supplied. Linked forms were not reviewed and are not reproduced as completed records. | Confirm applicable permit and material-change approval. |
| MOM - Duties in asbestos-related work | Full FAQ duty table: competent survey where required, ACM removal before demolition and approved asbestos removal contractor. Main duty summary only; actual survey, removal method, notifications, clearance and waste records not provided. This JSA does not authorise asbestos disturbance. | Resolve survey and separate approved asbestos removal before disturbance. |
| MOM - Requirements for hygiene monitoring | Main requirements: competent monitoring personnel, toxic substances, results and reporting, recommended frequency table and noise applicability. Material-specific exposure and actual monitoring frequency have not been determined. No workplace measurement is supplied. | Assess concrete dust and actual occupational exposure. |
| MOM - Hearing Conservation Programme | Full public answer identifying monitoring, source control, hearing protection/signs, training and audiometric examinations. General programme explanation. Actual exposure, monitoring and reporting duties need the workplace assessment; no noise reading or universal tool-use duration is supplied. | Apply actual noise assessment and hearing conservation. |
Selected public official sources were reviewed on 14 October 2026 within the recorded scope. No full consolidated legal audit, paid Singapore Standard, actual model manual, site inspection, engineering calculation or professional approval is claimed. Verify current detailed requirements and actual equipment/site records before use.
AI-generated reference material. It has not been verified or approved by a professional. Before use, a qualified person must review and adapt it to applicable Singapore requirements, the actual equipment and site, and approved safe work procedures.
10. PDF use and frequently asked questions
PDF A covers basic task controls; B focuses on technical failures; C covers supervision, records and handover. The article has eight stages with four items per main cell; each PDF has six key stages with three items per main cell. P/S/R/A, measurements, confirmations and signatures remain blank for actual site assessment.
Content group ID
jsa-structure-demolition
What must be confirmed for Survey and plan?
Required controls: Engineer staged sequence; Assess plant and debris loads; Design support through floors; Special plan for prestress. Evidence to record: Survey and drawings; Stage load checks; Support design; Engineer release.
What must be confirmed for Check machine?
Required controls: Follow model instructions; Verify coupler engagement; Inspect without hand leak test; Check cab and safety devices. Evidence to record: Machine and breaker IDs; Coupler test record; Hose defect status; Protection suitability.
What must be confirmed for Break in sequence?
Required controls: Follow approved stages; Use suitable shielding; Keep cab outside danger; Stop before changing sequence. Evidence to record: Current stage drawing; No people in zone; Support condition; Stage hold point.
What must be confirmed for Stop and hand over?
Required controls: Lower and secure attachment; Isolate per manufacturer; Secure remaining structure; Record defects and handover. Evidence to record: Isolation verification; Residual-stability record; Equipment defects; Next-stage release.
Has a professional verified or approved this document?
No. Public sources and editorial, layout and consistency checks were reviewed using AI. No site inspection or professional technical approval has been performed. Obtain appropriate professional review before use.
Singapore application
Read A, B and C together with all eight JSA stages and the approved work procedure. The sheets are complementary extracts, not separate work authorisations.
11. Authorship and revision history
AI-generated reference material. It has not been verified or approved by a professional. Before use, a qualified person must review and adapt it to applicable Singapore requirements, the actual equipment and site, and approved safe work procedures.
| Date / edition | Authorship and scope | Professional approval |
|---|---|---|
| 2026-07-26 / Korean source | Original topic and educational illustration retained as references. Source content is unchanged. | Not asserted |
| 14 October 2026 / Singapore 1.0 | Added Singapore BCA/QP demolition scope, structural appraisal and asbestos/exposure gates with staged residual-stability acceptance. | Not performed |
Source topic: https://smartjsabridge.com/ko/case-study/jsa-structure-demolition