The effects of shaft mud cake and bottom sediment on bearing capacity of bored pile are simulated by using FEM software. Based on the calculated results of single pile bearing capacity under the conditions of different thicknesses and elastic moduli of bottom sediment

the effect rule of sediment on bearing capacity of bored pile is studied. The calculated results show that the effect of thickness of bottom sediment on bearing capacity is threshold and no more obvious than the elastic modulus when the thickness of sediment is over 300 mm.The effects of height and strength of mud cake on bearing capacity of bored pile are calculated by considering the effect of mud cake strength taken place of shaft friction deduction coefficient of shaft mud cake; and the results show that the main effect factor of mud cake on bearing capacity of bored pile is height of mud cake around pile shaft.