Product Overview

Summary: This Safe Operating Procedure sets out safe, consistent methods for undertaking foundation stabilisation works on Australian sites, including underpinning, grouting and ground improvement. It helps organisations manage geotechnical risks, protect workers and adjacent structures, and maintain compliance with WHS and engineering requirements during high‑risk excavation and structural support activities.

Foundation stabilisation is a critical activity in the Australian construction and maintenance sector, particularly where buildings or structures show signs of settlement, cracking or ground movement. The work often involves excavation near live services, temporary support of existing structures, use of heavy plant, and application of specialist techniques such as underpinning, micro‑piling, resin or cementitious grouting, and soil improvement. Without a clear, documented procedure, these operations can expose workers and the public to serious risks, including ground collapse, structural failure and contact with underground services.

This Foundation Stabilisation Techniques Safe Operating Procedure provides a detailed, step‑by‑step framework for planning and executing stabilisation works safely and efficiently. It guides your team through geotechnical assessment requirements, engineering sign‑off, site preparation, plant and equipment controls, sequencing of works, monitoring of movement and settlement, and verification of outcomes. By embedding WHS duties and Australian standards into everyday practice, this SOP helps businesses reduce the likelihood of structural incidents, improve coordination between contractors and engineers, and demonstrate due diligence to regulators, clients and insurers.

Whether you are rectifying subsidence in residential properties, stabilising foundations for commercial buildings, or protecting critical infrastructure such as retaining walls, bridges and service corridors, this SOP provides the practical controls and documentation structure you need. It supports safer decision‑making on site, clearer communication with workers and subcontractors, and a repeatable method for managing complex ground and structural risks in line with Australian best practice.

Key Benefits

• Ensure foundation stabilisation works are planned, engineered and executed in line with Australian WHS and structural requirements.
• Reduce the risk of ground collapse, structural movement and damage to adjacent properties during stabilisation activities.
• Standardise communication and coordination between engineers, site supervisors, plant operators and subcontractors.
• Improve documentation, traceability and evidence of due diligence for regulators, insurers and clients.
• Minimise project delays and rework by clearly defining sequencing, hold points, inspections and acceptance criteria.

Who is this for?

• Site Supervisors
• Construction Project Managers
• Civil Engineers
• Structural Engineers
• Geotechnical Engineers
• WHS Managers
• Forepersons
• Plant Operators (Excavators, Piling Rigs, Drill Rigs)
• Concrete and Grouting Crews
• Residential and Commercial Builders
• Maintenance Managers (Infrastructure and Facilities)

Hazards Addressed

• Ground collapse and trench wall failure during excavation and underpinning
• Uncontrolled structural movement or partial building collapse
• Contact with underground services (electricity, gas, water, communications)
• Struck-by and crush injuries from plant, lifting operations and heavy components
• Exposure to cementitious products, resins, grouts and associated chemical hazards
• Noise, vibration and airborne dust generated by drilling, piling and excavation
• Manual handling injuries from handling underpinning blocks, steel, bags of grout and equipment
• Working in confined or restricted spaces beneath structures
• Environmental contamination from spills, wash‑out water and grout escape
• Fatigue and reduced situational awareness during extended or staged stabilisation works

Included Sections

• 1.0 Purpose and Scope
• 2.0 Definitions and Key Terms
• 3.0 Roles, Responsibilities and Competency Requirements
• 4.0 Applicable Legislation, Standards and Codes of Practice
• 5.0 Pre‑Start Planning and Engineering Assessment
• 6.0 Site Investigation, Service Locating and Geotechnical Requirements
• 7.0 Risk Assessment and Safe Work Method Integration
• 8.0 Required Plant, Tools, Materials and Personal Protective Equipment (PPE)
• 9.0 Foundation Stabilisation Methods Overview (Underpinning, Piling, Grouting, Resin Injection, Soil Improvement)
• 10.0 Step‑by‑Step Procedure – Underpinning and Structural Support
• 11.0 Step‑by‑Step Procedure – Grouting, Resin Injection and Ground Improvement
• 12.0 Controls for Excavation, Shoring and Access Beneath Structures
• 13.0 Lifting, Handling and Use of Plant and Equipment
• 14.0 Monitoring of Structural Movement, Settlement and Vibration
• 15.0 Hazard Identification, Control Measures and Residual Risk Management
• 16.0 Environmental Controls (Run‑off, Spoil, Noise and Vibration)
• 17.0 Emergency Preparedness and Response (Ground or Structural Failure, Service Strike, Spill)
• 18.0 Inspection, Testing, Hold Points and Engineering Sign‑off
• 19.0 Training, Induction and Communication Requirements
• 20.0 Documentation, Records and Review of Stabilisation Works
• 21.0 Continuous Improvement and SOP Review Log

Legislation & References

• Model Work Health and Safety Act and Regulations (as implemented in each state and territory)
• Safe Work Australia – Code of Practice: Excavation Work
• Safe Work Australia – Code of Practice: Construction Work
• AS 2870: Residential slabs and footings
• AS 2159: Piling – Design and installation
• AS 4678: Earth-retaining structures
• AS 1726: Geotechnical site investigations
• AS/NZS 1170 series: Structural design actions
• AS/NZS 4801: Occupational health and safety management systems (superseded but commonly referenced)
• AS/NZS 1891 series: Industrial fall-arrest systems and devices
• AS 2601: The demolition of structures (for interface with partial demolition, where applicable)