(7) The characteristic axial pile resistance is determined from: R c ,k (s) = R b,k (s) + R s,k (s) = hb ◊ q b,k ◊ A b + Â hs ◊ q s,k,i ◊ As,i
(5.6)
i
where: Ab As,i qb,k qs,k,i ηb ηs Rc,k(s) Rb,k(s) Rs,k(s) ssg* ssg
nominal pile base area, for steel section piles as shown in Figure 5.5; nominal pile shaft area in stratum i; for steel section piles as shown in Figure 5.5 with the effective circumference U; characteristic value of the base resistance, derived from Tables 5.1 and 5.3; characteristic value of the skin friction in stratum i, derived from Tables 5.2 and 5.4; base resistance model factor from Table 5.5; skin friction model factor from Table 5.5; settlement-dependent, characteristic compression pile resistance; settlement-dependent, characteristic pile base resistance; settlement-dependent, characteristic shaft resistance; characteristic settlement at which mobilisation of the ultimate skin friction for the settlement-dependent, characteristic pile shaft resistance begins; limit settlement for the settlement-dependent, characteristic pile shaft resistance (ssg = sg).
Figure 5.5 Nominal values of pile base areas and pile shaft areas of steel sections
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