Mechanism Of Vertical Uplift Bearing Capacity Of Bored Pile Is Studied

In engineering, as a form of uplift pile foundation uplift is widely used. Screw pile is a new pullout pile, Screw pile foundation having a hole in its construction, high quality, less pollution, etc, is widely used in foundation engineering municipal construction, roads and bridges and high-rise buildings, etc. Threaded screw pile exist curve increases the contact surface between the pile and the soil, increasing the pile side friction, thereby increasing the bearing capacity of the pile pullout. But, the pull-out characteristic of screw pile curve also lack of systematic study, at the same time on the properties of pull-out screw pile research have nothing better to guide the engineering practice, in order to better development curve as a pull-out screw pile foundation, it is necessary for curve of screw pile bearing mechanism for further study. In this paper, in reference to the curve based on the study of the vertical uplift bearing capacity of bored pile, we conducted a curve of screw pile indoor model test, and based on the results of the indoor model test and resources, system analyzed the curve of the screw under the condition of different parameters of the screw pile vertical uplift bearing mechanism, while using the finite element software ABAQUS to curve vertical pull-out screw pile bearing mechanism were studied. This article main research content is as follows:First of all, in this paper, based on the similar theory of model test, Using a certain relationship between the similarity theory and similarity ratio, in this paper, considering soil was used to simulate the foundation soil, and according to the related literature and the curve of screw pile the corresponding parameter to design the linear model of the pile、curve of screw pile model、Test tank model、Loading device and the corresponding test and data measurement process.The second, through the indoor model test measurement data analysis, such as linear pile diameter and thread width and thickness of the curve of different screw pile bearing capacity of pile under vertical load mechanism into full play, it is concluded that pile top load - settlement、pile axial force distribution、The distribution of resistance on pile side of pile and soil pressure situation. The experimental results showed that:Curve of screw pile is compared with the same outer diameter and inner diameter straight pile effectively improved the pull-out bearing mechanism of the pile, effectively improve the pile pulling force; Spiral width within a certain range, along with the increase of the width of the spiral uplift bearing capacity of bored pile is larger; The thickness of the screw within a certain range, with the increase of the thickness of the spiral uplift bearing capacity of bored pile had no obvious change.At last, combining with indoor model test, ABAQUS is used to establish the vertical pull loads on the finite element model of pile - soil foundation, according to the load rating load for finite element analysis. The calculation results show that: Numerical simulation in the various loads of numerical simulation to get the tendency of the displacement and displacement of pile head and indoor model test are consistent, by comparing the further affirmed the ABAQUS finite element simulation on the accuracy of the interaction of piles and soil.