A new simplified computing formula of uplift capacity of enlarged base pile in layered soils is deduced according to power law slip surface premises and based on limit equilibrium method. The comparison between theoretical predictions which is in accordance with the simplified formula and other theoretical methods and centrifuge tests and in situ test for enlarged base pile is illustrated in detail. According to the comparative analysis

the following conclusions are gained: the deduced theoretical formula is an integrated simplified method of several failure surface premises and corresponding formulas. The theoretical prediction by simplified method while power N=10 in dense sand and N→∞ in loose sand is consistent with centrifuge tests results. Short pile(L/d<20) and long pile(L/d>20) should be distinguished because in situ test has obvious measurement effect in layered soils. The simplified method is accurate for short pile while power N→∞; on the other hand

this formula needs to be revised using layered discount coefficient for long pile. It is reasonable that layered discount coefficient equals to 0.5 in sand and 0.6 in clay.