Level 1 Inspection And Testing: Reliability Or Liability?

In 1990, when the earthworks Guidelines were first introduced, adoption of Level 1 Inspection and Testing in accordance with AS3798 was seen as the panacea for standard practice in the industry for the determination of compliance with specification requirements for compaction of fill. Since then, the use of Level 1 responsibility has become widespread on large earthworks contracts where an engineered fill is the required product. Reliability of the engineering performance of compacted fill was seen as the main selling point for justification to principals.

Experience has shown there are many limitations associated with implementation of the concept outlined in the Guidelines, so that the result is a liability for many stakeholders in an earthworks contract. This paper explores some of the challenges associated with implementation of Level 1 Inspection and Testing, as it is now known, which can reduce the goal of ‘reliability’ to a ‘liability’ for the stakeholders in the earthworks contract. These challenges include:

• physical limitations of workload for the Geotechnical Inspection and Testing Authority/Geotechnical Testing Authority;
• whether sufficient testing is completed to reliably identify problem “hot spots”;
• whether sufficient data is recorded to enable audit of traceability of completed testing;
• the low relative cost of testing in relation to contract value;
• whether remuneration rates for Geotechnical Testing Authority staff are sufficient in relation to siteoperatives to resist temptations;
• what liabilities may arise for the stakeholders from defects or problems in the finished product;
• what remedies may be available to rectify the challenges;
• whether results of testing some time after completion are still representative;
• whether the GITA/GTA should be part of the contractors QA/QC system to enable better integration.

The authors do not intend to provide answers to these challenges, but to initiate some discussion.