CPT-based pile shaft friction in calcareous sands of western Indian offshore

2015 ◽  
pp. 619-624
Author(s):  
R Mahanta ◽  
R Ghanekar ◽  
A Kumar
Keyword(s):  
Pile Shaft ◽  
Calcareous Sands ◽  
Shaft Friction

Lateral stress changes and shaft friction for model displacement piles in sand

2005 ◽  
Vol 42 (4) ◽  
pp. 1039-1052 ◽  
Author(s):  
Barry M Lehane ◽  
David J White
Keyword(s):  
Shear Band ◽  
Effective Stress ◽  
Static Load ◽  
Lateral Stress ◽  
Interface Shear ◽  
Pile Installation ◽  
Pile Shaft ◽  
Centrifuge Tests ◽  
Stress Changes ◽  
Shaft Friction

The paper describes a series of tests performed in a drum centrifuge on instrumented model displacement piles in normally consolidated sand. These tests examined the influence of the pile installation method, the stress level, and the pile aspect ratio on the increase in lateral effective stress on the pile shaft during static load testing to failure. A parallel series of constant normal load and constant normal stiffness (CNS) laboratory interface shear experiments was performed to assist interpretation of the centrifuge tests. It is shown that although the cycling associated with pile installation results in a progressive reduction in the stationary horizontal effective stress acting on a pile shaft and densification of the sand in a shear band close to the pile shaft, this sand dilates strongly during subsequent shearing to failure in a static load test. The dilation (the amount of which depends on the cyclic history) is constrained by the surrounding soil and therefore leads to large increases in lateral effective stresses and hence to large increases in mobilized shaft friction. The increase in lateral stress is shown to be related to the radial stiffness of the soil mass constraining dilation of the shear band and to be consistent with measurements made in appropriate CNS interface shear tests. The paper's findings assist in the extrapolation of model-scale pile test results to full-scale conditions.Key words: sand, displacement pile, centrifuge tests, shaft friction.

scholarly journals Experimental Study on the Behavior of X-Section Pile Subjected to Cyclic Axial Load in Sand

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yiwei Lu ◽  
Hanlong Liu ◽  
Changjie Zheng ◽  
Xuanming Ding
Keyword(s):  
Axial Load ◽  
Large Scale ◽  
Cross Sectional Area ◽  
Load Test ◽  
Dynamic Responses ◽  
Scale Model ◽  
Loading Frequency ◽  
Sectional Area ◽  
Cross Sectional ◽  
Shaft Friction

X-section cast-in-place concrete pile is a new type of foundation reinforcement technique featured by the X-shaped cross-section. Compared with a traditional circular pile, an X-section pile with the same cross-sectional area has larger side resistance due to its larger cross-sectional perimeter. The behavior of static loaded X-section pile has been extensively reported, while little attention has been paid to the dynamic characteristics of X-section pile. This paper introduced a large-scale model test for an X-section pile and a circular pile with the same cross-sectional area subjected to cyclic axial load in sand. The experimental results demonstrated that cyclic axial load contributed to the degradation of shaft friction and pile head stiffness. The dynamic responses of X-section pile were determined by loading frequency and loading amplitude. Furthermore, comparative analysis between the X-section pile and the circular pile revealed that the X-section pile can improve the shaft friction and reduce the cumulative settlement under cyclic loading. Static load test was carried out prior to the vibration tests to investigate the ultimate bearing capacity of test piles. This study was expected to provide a reasonable reference for further studies on the dynamic responses of X-section piles in practical engineering.

Minimization of contact pressure for hub–shaft friction pair

2015 ◽  
Vol 36 (5) ◽  
pp. 404-408 ◽  
Author(s):  
V. M. Mirsalimov ◽  
P. E. Akhundova
Keyword(s):  
Contact Pressure ◽  
Friction Pair ◽  
Shaft Friction

Shaft Friction from Instrumented Displacement Piles in an Uncemented Calcareous Sand

2012 ◽  
Vol 138 (11) ◽  
pp. 1357-1368 ◽  
Author(s):  
Barry M. Lehane ◽  
James A. Schneider ◽  
Jit Kheng Lim ◽  
Giuseppe Mortara
Keyword(s):  
Calcareous Sand ◽  
Shaft Friction

Prediction of pile shaft resistance using cone penetration tests (CPTs)

2012 ◽  
Vol 45 ◽  
pp. 74-82 ◽  
Author(s):  
Mohammad Hassan Baziar ◽  
Armin Kashkooli ◽  
Alireza Saeedi-Azizkandi
Keyword(s):  
Cone Penetration ◽  
Shaft Resistance ◽  
Pile Shaft ◽  
Cone Penetration Tests ◽  
Penetration Tests
Sign in / Sign up

Export Citation Format

Share Document