Preliminary Report on the Effect of Pre-Boring on the Mobilized Friction Capacity of Pile Foundation Hydraulically Jacked into Expansive Soil
Abstract: Pre-drilling was
performed to reduce lateral earth pressure generated by pile foundation
hydraulically jacked into expansive soil. Nineteen prestressed-precast spun
concrete pile with diameter of 800 mm were penetrated into expansive soil up
the depth of 40 m. Pre-drilling with diameter of 700 mm was carried out up to
the depth of 12.5 m. Penetration loads required to install the piles, which was
displayed on the built-in pressure panel, were recorded every 1 m interval. The
load that was consisted of merely shaft friction was then used to find out the
mobilized skin friction between pile shaft and its surrounding soils. The
calculated mobilized skin friction was correlated to the value of Standard
Penetration Test (NSPT) and compared to Decourt formula. The result shows that
skin friction calculated using Decourt formula relatively conservative compared
to those determined from the records of field penetration. The upper bound of
mobilized skin friction can be defined by modifying Decourt formula.
Author: Budi G.S
Journal Code: jptsipilgg150011
