Proceedings of DFI-India 2019: 9th Conference on Deep Foundation Technologies for Infrastructure Development in India, (DFI)
Implication of Site Investigation on Piles Socketed in Weathered Rock
Kuppala Venkata Sivannarayana, G. Gowthami and E. Suresh
Bored cast-in-situ concrete piles socketed in rock offer best foundation solutions under situations involving heavy loads and under sub-surface conditions where a layer of loose soil overlies bedrock. The quality and reliability of rock data from the geotechnical investigation have become more important and the use of insufficient and incorrect data will have a huge impact on substructure design. This may lead to either uneconomical pile designs or on the contrary pose construction difficulties. This is well established in the development of one of the important major bridge structures across Balram River. This bridge in the state of Gujarat was designed as part of package 3R by the Dedicated Freight Corridor Corporation of India Limited. The initial stage investigation was performed by the poor quality of drilling resulted in poor core recovery and insufficient rock data. This has resulted in uneconomical geotechnical recommendations for substructure. Based on investigation data, the piling equipment mobilized at the site has difficulties to drill through this rock and form pile socket. Hence stage II investigation was proposed using hydraulic rig, double tube core barrel with controlled drilling at the site to get maximum core recovery. This improvement in investigation resulted in getting complete detail about the rock characteristics to plan suitable piling equipment & optimize the substructure design. Deploying suitable tools for investigation experienced drilling operator, performing drilling operation as per guidelines outlined in Indian Standards and capturing the drilling information is very important.
|article #3302; publication #1059 (India2019)|