Study On The Selection Of Reasonable Bridge Pile Foundation Length Based On Pile Group Effect In The Loess Area

Friction type of pile foundation is widely used in the loess area, because of the special engineering properties in this area. In practical engineering, the bottom of the pile foundation can’t provide enough bearing capacity, because of the depth of loess layer, thus increasing pile length to meet the demand of the bearing capacity of pile foundation. To the opposite, when pile length exceeds a certain length, it’s contribution to less bearing capacity. And according to the existing bridge specification to design pile foundation is not perfect and unreasonable. Therefore, in this article, through the finite element software ANSYS to analyze the reasonable pile length of pile foundation in the loess area. The main works are as follows:Based on the available parameters of loess, using ANSYS software to establish model of the single pile in the loess region, analyze the stress on the different pile length, and then analyze the factors affecting the bearing capacity of pile foundation, in order to determine the scope of the reasonable pile length of single pile;According to the existing bridge pile foundation specification calculating the bearing capacity of single pile, and comparing the numerical calculation of single pile to point out the shortage of the existing specifications;Using ANSYS to establish pile group model on the basis of the single pile model, and analyze the group pile effect.Comparing the bearing capacity and settlement of different pile length and pile spacing of 2 x 2, 3 x 3, 4 x 4 group pile. Analyzing the axial force of pile and the load sharing ratio of pile cap, in order to determine the scope of reasonable pile length and pile foundation in loess area.