Pile Integrity Tests as a Tool in Quality Control of Bored Cast In Situ Pile Foundations-Paper

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The paper presents a case study showing how pile integrity testing (PIT) helped diagnose failed load tests on large-diameter bored cast-in-situ piles for a coastal effluent-conveyance structure in Kutch, Gujarat.<br /><br />Initial 1,200 mm diameter test piles with rock sockets of 1D and 3D (where D is the pile diameter) failed to meet the required axial capacity. A 5D socket pile passed, but using such deep sockets would substantially increase construction costs. Confirmatory ground investigations found no major change in soil conditions to explain the failures.<br /><br />PIT results revealed reduced pile cross-sections in the failed 1D and 3D piles, indicating construction defects such as necking. The 5D pile had a reasonably uniform shaft. The investigation therefore identified poor construction quality—not inadequate design assumptions about load transfer—as the cause of the initial failures.<br /><br />Additional 1D and 3D piles were constructed under stricter quality control. Both passed load tests, demonstrating that the shallower sockets could satisfy design requirements when piles were properly executed.<br /><br />The authors conclude that PIT is a practical quality-control tool for assessing a test pile before undertaking costly, time-consuming load testing. They recommend applying PIT to test piles and, in accordance with relevant standards, using integrity testing to screen working piles and identify those requiring further investigation or testing. The case highlights the importance of competent investigation and testing agencies, qualified site supervision, and rigorous control during test-pile construction.

Keywords

pile integrity testing

bored cast-in-situ piles

load test failure

Kutch Gujarat

rock socket

necking

pile defects

construction quality control

axial capacity

coastal effluent-conveyance structure