TY - JOUR
T1 - Centrifuge research of countermeasures to protect pile foundations against liquefaction-induced lateral spreading
AU - Abdoun, Tarek
AU - Dobry, Ricardo
AU - Zimmie, Thomas F.
AU - Zeghal, Mourad
N1 - Funding Information:
Several of the developments and results presented were obtained over a period of several years at the RPI centrifuge by Drs. P.-V. Kallou, C. Oskay, A. Pamuk, R. Ramos and Y. Wang; this contribution is gratefully ackrlowledged. Discussions with Prof. Thomas D. OYRourkeo n soil pressures on piles due to lateral spreading were also very helpful. Much of the planning and interpretation of the passive site remediation experiments was done in cooperation with P. Gallagher of Drexel University. All of this help is cheerfully acknowledged. The research on centrifuge pile modelling and interpretations at RPI has been supported over several years by grants from: The Multidisciplinary Center for Earthquake Engineering Research, MCEER (previously NCEER), the National Science Foundation, NSF, and the Federal Highway Administration (FHWA). This support is also most gratefully acknowledged.
PY - 2005/1
Y1 - 2005/1
N2 - Repeated experience of foundation and superstructural damage during earthquakes associated with ground failure and liquefaction, have shown the importance of lateral spreading and especially of the presence of a shallow nonliquefiable soil layer as a cause of damage. Typically such strong nonliquefiable layer or crust, riding on the liquefiable soil where the lateral spread actually occurs, pushes laterally against the piles and pile cap, inducing large lateral forces, deformations and bending in the foundation. The effects depend on the free field deformation, characteristics of the nonliquefiable layer and foundation, and characteristics of the superstructure. For an existing pile foundation, the first step is to verify if the pile foundation has enough stiffness and strength to resist the soil lateral forces, and especially the passive thrust applied by the nonliquefiable layer, with acceptable foundation displacement and rotation and no damage to the foundation elements, in which case no countermeasures are needed. If this evaluation concludes that the foundation does not possess the required stiffness and strength to prevent distress, three mitigation strategies are often used: (i) Remediation countermear sure of the liquefiable soil at the site to prevent the free field liquefaction and lateral spreading from occurring in the first place; (ii) retrofitting of the foundation by reinforcing it, for example by adding piles or strengthening the existing piles; and (iii) isolation of the foundation, and especially of the pile cap, from the nonliquefiable layer in the free field by a retrofitting countermeasure where a “soft fuse” such as a soft soil or other material or device are installed at shallow depths near the foundation, hence limiting the lateral force applied to the piles and pile cap to a low value which minimises the deformation and bending of the foundation. The paper discusses these countermeasure strategies through several series of centrifuge model tests of single piles and pile groups conducted with the participation of the authors at the RPI geotechnical centrifuge.
AB - Repeated experience of foundation and superstructural damage during earthquakes associated with ground failure and liquefaction, have shown the importance of lateral spreading and especially of the presence of a shallow nonliquefiable soil layer as a cause of damage. Typically such strong nonliquefiable layer or crust, riding on the liquefiable soil where the lateral spread actually occurs, pushes laterally against the piles and pile cap, inducing large lateral forces, deformations and bending in the foundation. The effects depend on the free field deformation, characteristics of the nonliquefiable layer and foundation, and characteristics of the superstructure. For an existing pile foundation, the first step is to verify if the pile foundation has enough stiffness and strength to resist the soil lateral forces, and especially the passive thrust applied by the nonliquefiable layer, with acceptable foundation displacement and rotation and no damage to the foundation elements, in which case no countermeasures are needed. If this evaluation concludes that the foundation does not possess the required stiffness and strength to prevent distress, three mitigation strategies are often used: (i) Remediation countermear sure of the liquefiable soil at the site to prevent the free field liquefaction and lateral spreading from occurring in the first place; (ii) retrofitting of the foundation by reinforcing it, for example by adding piles or strengthening the existing piles; and (iii) isolation of the foundation, and especially of the pile cap, from the nonliquefiable layer in the free field by a retrofitting countermeasure where a “soft fuse” such as a soft soil or other material or device are installed at shallow depths near the foundation, hence limiting the lateral force applied to the piles and pile cap to a low value which minimises the deformation and bending of the foundation. The paper discusses these countermeasure strategies through several series of centrifuge model tests of single piles and pile groups conducted with the participation of the authors at the RPI geotechnical centrifuge.
KW - Centrifuge
KW - Lateral spreading
KW - Liquefaction-induced
KW - Pile foundations
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U2 - 10.1080/13632460509350581
DO - 10.1080/13632460509350581
M3 - Article
AN - SCOPUS:23944484491
SN - 1363-2469
VL - 9
SP - 105
EP - 125
JO - Journal of Earthquake Engineering
JF - Journal of Earthquake Engineering
ER -