• Review pile construction records and expected pile length

• Prepare pile head by removing loose concrete or debris

• Mark impact and sensor locations

• Install velocity or acceleration sensor on pile head

• Verify sensor coupling and signal stability

• Apply low energy hammer impacts to pile head

• Record reflected stress wave signals

• Repeat impacts to ensure consistent results

• Filter and process time-domain signals

• Identify toe reflection and calculate pile length

• Detect impedance changes indicating defects

• Assess severity and depth of anomalies

• Compare results with design length and soil profile

• Classify pile integrity status

• Issue technical interpretation and report

Low Strain Pile Integrity Testing (PIT) is a rapid, non-destructive method used to evaluate pile length, continuity, and major defects. It is particularly useful for quality control in large projects where hundreds of piles must be verified efficiently. PIT is widely applied in Sri Lanka to detect issues such as cracks, necking, or incomplete pile sections, especially in varying soil conditions.

The method involves a light hammer impact on the pile head, generating stress waves that propagate through the pile. Reflections caused by the pile toe or any abrupt changes in cross-section are recorded by velocity or accelerometer sensors. Signal analysis allows engineers to estimate pile length, detect major defects, and assess pile integrity without causing structural damage.

The resulting report provides a clear assessment of pile condition, including locations of anomalies and recommendations for further testing or remedial work. PIT testing supports construction quality assurance, reduces the risk of structural failure, and ensures compliance with engineering standards.