Trench & Excavations Stability Inspections
Atlas Engineering and Technology Group (AETG) understand that trench and excavation stability inspections are critical to ensuring the safety of workers and the integrity of structures during excavation activities for temporary and permanent works. Excavations, including trenches for foundations, utilities, or other purposes, can be dangerous if not properly assessed and monitored. The main goal of these inspections is to confirm that the excavation is stable, does not pose a risk of collapse, and that appropriate safety measures are in place to protect workers.
How Can AETG Help?
Assessing Soil and Subsurface Conditions: Inspecting the soil type and its ability to withstand the loads placed on it during excavation. Evaluating the presence of groundwater or other factors that could affect soil stability.
Ensuring Safe Excavation Practices: Ensuring that proper excavation techniques and safety protocols are being followed to prevent cave-ins and accidents. Confirming that the excavation depth, width, and slope adhere to safety regulations and standards.
Verifying Proper Shoring, Shielding, and Bracing: Ensuring the correct installation and use of protective systems like shoring, shielding, and bracing to prevent soil collapse.
- Mitigation Strategies Trench Inspections and excavation assessments can be provided by experienced geotechnical engineers to advise on potential impacts to adjacent structures and provide impact minimisation strategies and appropriate or alternative excavation methods.
Services AETG Provide
Pre-Excavation Inspections:
- Soil and Site Condition Assessment: Before starting excavation, assess the soil type (e.g., sandy, clayey, or rocky), moisture content, and groundwater levels. Soil classification determines the stability of the trench and the type of protective systems required.
- Groundwater and Drainage Evaluation: Check for groundwater seepage that could compromise trench stability, requiring dewatering systems or other mitigation methods.
Excavation and Shoring Inspection:
- Benching or Battering: If benching or battering is used as a protective measure, inspect the excavation’s side walls to confirm the correct dimensions. The angle of repose typically depends on the soil type.
- Protection Systems: Ensure that protective systems such as trench shields or shoring boxes are in place for deep excavations. These systems should be designed and installed according to safety guidelines.
Excavation Depth and Width: Inspect the trench to confirm it is not deeper than allowed by regulations without appropriate protective systems in place. Verify the width is sufficient for worker safety and equipment.
In-progress inspections During Excavation:
- Trench Wall Inspection: During excavation, the trench walls must be inspected for signs of potential instability, such as cracking, bulging, or shifting soil.
Saturation and Soil Stability Monitoring: Continuously monitor for signs of soil saturation or excessive moisture, which could compromise excavation walls. If water is present, it may require immediate action (e.g. dewatering or installing additional bracing).
Post-Excavation Inspection:
- Trench Stability After Excavation: Post-excavation trench inspection is a critical step in ensuring the safety, stability, and compliance of trenching activities. After excavation, the trench is thoroughly inspected to assess its structural integrity, check for potential hazards, and ensure it meets regulatory and design standards.
Why Choose AETG for Trench & Excavation Stability Inspections?
Trench and excavation stability inspections are crucial for mitigating risks, safeguarding workers, and ensuring the structural integrity of the excavation site. These inspections must be performed routinely, both before and during excavation activities, to assess soil conditions, verify the proper installation of shoring and bracing systems, and confirm compliance with safety protocols. AETG can proactively identify and address potential hazards through rigorous inspections, which can prevent costly project delays and, most importantly, reduce the risk of injuries or fatalities resulting from trench collapses.
Successfully Completed Jobs by AETG to Date
✔ Proposed Pavement Upgrade - Mulgoa Rd, Regentville, NSW
The Excavation Inspection Report, prepared by AETG for Ferrycarrig Construction Pty Ltd, documents a site inspection conducted at Mulgoa Road, Regentville NSW, as part of the Mulgoa Road Upgrade project. The inspection focused on the stability of an excavation approximately 3.2 m wide, 5.0 m long, and 2.6 m deep, composed of silty clay. The shoring supports were found to be adequately installed, and no immediate stability concerns were identified. The excavation was deemed safe for personnel entry under specific conditions, including maintaining a 1.5 m buffer for vehicles and machinery, minimising vibrations, and retaining existing shoring. The report's validity is limited to one week post-inspection or until significant weather events occur, after which reinspection is recommended.
✔ Proposed High School Construction - Horrie Rd, Edmondson Park High School NSW
AETG was hired by Attcall Civil Contracting to conduct footing inspections for the proposed foundations of Building A in the Edmondson Park School Development. The on-site assessment, carried out by an AETG Geotechnical Engineer, aimed to evaluate the stability of the excavated foundations and determine the need for benching or battering. The inspection found that the excavated foundation material, consisting of silty clays and silty clay fill, was stable and well compacted. No signs of instability or collapse were identified, and the footings were reinforced and poured with concrete. It was advised that excavations should not remain open for more than one week to prevent changes in moisture conditions, and that further inspections may be required during inclement weather. Based on the observations, it was determined that benching or battering is not required, provided that loose and wet material is removed before concrete placement.
✔ Proposed Substation Construction - Waterloo Rd, Macquarie Park NSW
The Onsite Excavation Inspection Report by AETG, documents an inspection for Haslin Constructions Pty Ltd at Waterloo Rd, Macquarie Park NSW, as part of the Proposed Substation Development. The excavation, conducted for conduit installation, measured 2.4 m wide and 2.7 m deep, with no visible water accumulation or surface deformities. The inspection found no immediate stability concerns. Excavation layers included concrete slab, sandy gravel, various clays, and sandstone. Key recommendations included ensuring continued structural support at the northern wall using a mix of structural plywood and acrow props, filling any gaps between the excavation wall and plywood, restricting vehicle movement within the 2.0 m zone of influence, and promptly reinforcing displaced structural elements. The site was deemed safe for personnel entry provided these recommendations are followed.