Research On The Bearing Behavior Of Bored Rock-socketed Piles And Its Bearing Capacity Calculating Methods

The static-load-test datum of 36 rock-sockted piles is settled in this paper. According to the property of rock base, these piles are divided into two species, soft-rock-socketed pile (29 piles) and hard-rock-socketed pile (7 piles). Based on the research of the previous and active calculation methods of rock-socketed piles, it is considered that its beating capacity is consist of the total side resistance of the overlaid soil and rock, and the total pile tip resistance.The bearing behavior, the load transferring mechanism, and the influence factors are discussed in this paper, and then it is thought that the ratio of the pile length and its diameter l/d is the most weighted factor which influences the side resistance of the overlaid soil, and the ratio of the length of which part of the pile socketed in the rock and the its diameter h_r/d is the most important factor which influences the side resistance and the tip resistance of the rock.The functions of the soil side resistance coefficient ζ_s, of the soft-rock-socketed pile and the hard-rock-socketed pile are separately conducted though the statistics of these piles datum. The functions of the rock side resistance coefficient ζ_r and the tip resistance coefficient ζ_P are separately conducted though the same method.At last, the functions of ζ_s, ζ_r and ζ_P are inducted into the formula, and then the ultimate bearing capacity formula of rock-socketed pile, being related with l/d and h_r/d , are conducted.