This paper presents the results of measurements of total stress against the shaft and the base of a mandrel-driven cast-in-situ steel pile 57 m long, 508/457 mm in diameter, installed in NC clay. The pile was instrumented with 8 dilatometer cells (4 pairs at 5 m depth intervals) along the shaft and one dilatometer cell at the pile tip center. The cell readings (total stress) were taken during installation, subsequent reconsolidation and test loading to failure. During installation, driving was interrupted at various depths in order to take readings immediately after stopping driving and, at three different levels, after complete reconsolidation of the surrounding soil. The "initial" σh readings and the subsequent decay curves have been compared with the p0 readings and the subsequent decay curves against the side of a "standard" dilatometer blade, in order to explore the possibility of using DMT-p0 to get indications of σh against the pile at installation stage and subsequently. The total stress measured by the cell installed at pile tip has been compared to CPT-qc. Two loading tests to failure were performed on the pile at two different levels. The first loading test was performed with the pile tip in clay at 50 m depth, with the mandrel inside the steel shell, without concrete. The second one was performed with the pile tip in sand at 57 m depth on the pile filled with concrete.
|Titolo:||Field Studies of an Instrumented Full-Scale Pile Driven in Clay|
|Data di pubblicazione:||1994|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|