Km. Hassan et Mw. Oneill, SIDE LOAD-TRANSFER MECHANISMS IN DRILLED SHAFTS IN SOFT ARGILLACEOUS ROCK, Journal geotechnical and geoenvironmental engineering, 123(2), 1997, pp. 145-152
Elastic-plastic axisymmetric finite-element analyses were performed to
investigate the side load-transfer mechanism of drilled shafts socket
ed into cohesive intermediate geomaterials (very hard clays/very soft
rocks). The roughness of the concrete-geomaterial interface was modele
d explicitly by assuming sinusoidal undulations along a discontinuous
surface. Smooth interfaces were also modeled. The results of the analy
ses indicated that the elastic response of rough sockets extends as th
e initial normal interface stress, sigma(n), increases. Value sigma(n)
does not affect the maximum unit side resistance, f(max), of sinusoid
al sockets significantly, as shearing of the geomaterial occurs by gou
ging through the geomaterial asperities emanating from locations betwe
en the roots and crowns soon after separation occurs at the backs of t
he asperities. However, sigma(n) is a principal factor affecting f(max
) in smooth sockets. The sliding friction at the interface plays a maj
or role in the development of load transfer, and internal friction of
the geomaterial plays a less significant role. The behavior of smeared
sockets was also investigated. A relatively Small thickness of residu
al remolded geomaterial along a rough interface was found to reduce lo
ad transfer significantly.