Section 3: Quality Assurance and Quality Control

Overview

Perform Quality Assurance and Quality Control (QA-QC) at all levels to ensure quality of data produced and deliverables. QA-QC shall be conducted in accordance with drilling or investigation contract documentation, but generally include the protocol outlined in this section.

Sampling

A minimum of three-man crew consisting of a driller, driller’s helper, and a logger shall perform the sampling and logging on the field. To ensure consistency, the same crew shall complete the drilling, sampling, and logging on a project. Photo log of all samples shall be provided to the client along with the field logs for verification of consistency of the logging.
Each crew shall maintain a copy of the TxDOT Geotechnical Manual and relevant Test Methods (TxDOT, AASHTO, or ASTM) required for drilling, sampling, and classification of soil and bedrock materials.

Logger Qualification

A qualified logger shall perform all sampling, identification of the drilled material, and logging the soil profile. The following minimum requirement shall be used for a logger:
  1. A geologist or Engineer-in-training with at least two years of related experience in local soils and bedrock identification, testing, and data collection techniques, or
  2. An engineering technician with at least five years of verifiable experience in local soils, bedrock description, testing, and data collection techniques.
Drilling Logs and test data presented must be reviewed and evaluated by a registered professional engineer.

Tester Qualification

Engineering technicians performing laboratory tests shall be qualified in accordance with the TxDOT Quality Assurance Program or other TxDOT approved programs. Approval of the engineering technician by TxDOT or other TxDOT approved programs does not relieve the professional/geotechnical engineer of the responsibility of ensuring the engineering technician is fully qualified to correctly perform the laboratory testing.

Equipment

Laboratory equipment used for testing shall be calibrated in accordance with TxDOT, National Institute of Standards (NIST), AASHTO, and ASTM requirements and the Geotechnical Engineer shall ensure the equipment meets these requirements.

Laboratory Accreditation

Laboratory testing shall be performed at TxDOT or AASHTO certified/accredited laboratories.