Analysis On Reliability Of Pile Under Inclined Loads

The bridge piles are often loaded by the composite effects of vertical and horizontal loads. The vertical loads, horizontal loads and other factors relevant to the behavior of pile, as natural or artificial variables, are variant in statistics. But statistical variability of vertical loads, horizontal loads and other factors, is seldom applied to the study of behavior of pile under inclined loads by engineers. Therefore, in the paper, the statistical variability of all factors is applied to the study of behavior of pile under inclined loads.Firstly, behavior and destroying mechanism of pile under inclined loads are systematically discussed based on summary of research on pile under inclined loads home and abroad, and then a power series solution for displacement and stress calculation of pile under inclined loads in layered soils is presented. Based on the solution, the calculation of soil reaction force at the flank and bottom of piles, vertical and horizontal displacement of piles and maximal bending moment of piles is concluded. Secondly, based on the structure reliability theory, eight types of failure modes of pile under inclined loads are presented, and then corresponding limiting state and limit function of every failure mode are established. Thirdly, aimed at the high-nonlinear and recessive of all limit functions, an improved response surface method based on high-order response surface function is presented for reliability calculation, which needed less calculation time and had better precision by comparison with other habitually used methods. Finally, a computer program for reliability indices calculation of pile under inclined loads is developed, and based on results of calculation, influencing factors and developing rule of reliability indices of pile under inclined loads have been discussed, and some beneficial conclusions have been reached.