Proceedings - Fifth International Conference & Exhibition on Piling and Deep Foundations, 1994, Bruges, Belgium, (DFI)
Pile loading tests and corrective actions for anomalies detected in large bored piles
M. Bustamante & Y. Zaczek
Anomalies have been detected during the construction of large bored piles (0.75 to 1.10 m in diameter) on an industrial site. According to the geotechnical investigation, the site consisted of a layer of industrial wastes and backfill, 10 m of sandy gravels with lenses of peaty clay covering the shally bedrock. Cavities and concreting anomalies of the lower end of the piles were revealed after a series of continuous core drilling through the shaft of some piles. Full instrumented static loading tests have been therefore performed to measure the deformation of the piles at selected levels during the loading steps. The unit skin friction of the different soils layers have been deduced as well as the percentage of the load transmittd to the lower part of the shaft. The piles, originally designed as tip piles, were recomputed according to the skin friction values deduced from the test pile. For some settlement sensitive structures, it has been decided to grout the lower end of the inclined piles, together with their surrounding soils. The vertical piles, not so critical for the stability, were accepted as friction piles.
|article #818; publication #36 (IC-1994)|