Evaluation of Axial Load Capacity of Driven Piles in Soft Soils using CPT and Static Analysis Methods

摘要

This paper presents the comparison of axial load capacity of friction piles driven into soft Louisiana soils predicted using different CPT methods and static analysis. Thirty square Precast-Prestressed-Concrete (PPC) piles were investigated in this study. Since Louisiana soils are mainly consists of clay and silty clay deposits, the side friction (Q_s) dominates the total ultimate bearing capacity (Q_(ult)) compared to the end bearing capacity (Q_b). The axial capacities of the investigated piles were predicted using three direct CPT methods: Schmertmann method, Bustamante and Gianeselli (LCPC) method, and De Ruiter and Beringen method. The static analysis was also conducted to predict the ultimate bearing capacities of selected piles using a-method and Nordlund method. The predicted bearing capacities were compared with the measured bearing capacities from static load tests at field. Davisson interpretation criterion was used to determine the measured ultimate bearing capacity of the investigated piles. The analysis shows that the average method is the preferred method when CPT pile capacity is used.