> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/technical-background/soil-structure-interaction/lateral-soil-models/liquefied-sand-rollins-rollins-et-al-2005.md).

# Liquefied Sand (Rollins) \[Rollins et al., 2005]

*p-y* curve model recommended by \[Rollins et al., 2005], derived from full-scale lateral load tests, is used to analyze piles subjected to lateral loads in the presence of a liquefied sand layer. The resulting *p-y* relationship does not require input values other than pile width.

$$
\tag{1}
p = p\_dA(By)^{C}
$$

where,

$$p$$ = horizontal soil resistance per unit length in (kN/m)

$$p\_d$$ = pile diameter correction factor

$$y$$ = horizontal displacement in (mm)

$$A,B,C$$ = coefficients

$$
\tag{2}
A = 3\*10^{-7}(z+1)^{6.05} \quad B = 2.8(z+1)^{0.11} \quad C = 2.85(z+1)^{-0.41}
$$

where,

$$z$$ = depth (m)

$$
\tag{3}
p\_d = 3.81ln(b) + 5.6
$$

$$b$$ = diameter or width of the pile or shaft (m)

The pile diameter correction factor, $$p\_d$$, is equal to 1 when the pile diameter is 0.3 m. According to\[Rollins et al., 2005], Eqn. (2) may not be appropriate for foundations with diameters smaller than 0.3 m or greater than 1.0 m. Moreover, the maximum horizontal resistance, $$p\_u$$, for the tested piles is 15 kN/m. In other words, Eqn. (1), with $$p\_d$$ = 1, equals 15 kN/m.

***

\[Rollins et al., 2005] Rollins, K. M., Gerber, T. M., Lane, J. D., and Ashford, S. A. (2005). Lateral resistance of a full-scale pile group in liquefied sand. *Journal of Geotechnical and Geoenvironmental Engineering*, 131(1):115–125


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