| Because of its proficient piling technology, long and large diameter bored pile has become one of the most common type of bridge pile foundation, the control technology of vertical degree is one of the key technologies during the whole boring process.If the pile verticality does not control properly, it will directly affect the installation of the catheter and reinforcement cage,the quality of the boring pile and the play of the pile bearing capacity, and so on.Based on principles of pile-soil load transfer system and the specific geological conditions,the effect of variation for the vertical degree on the bearing capacity of long and large diameter bored pile is studied deeply and systematically using ANSYS software.The main work in the thesis is as follows:1.The engineering geology and the main design specifications of pile foundation of the Pingtan Strait Bridge is systematically collected, it can provide a theoretical basis to the establishment of the calculation scheme of numerical analysis, the found of the calculation model and the selection of material parameters;2.Using ANSYS finite element techniques,the effect of vertical degree on bearing capacity under the different conditions is analysed in the thesis,it can provide theoretical support to the proposal of the suggested value of vertical degree control;3.Based on the results of FEM analysis and theoretical calculation, the suggested value of vertical degree control of the pile is proposed,and the evaluation effect on engineering of the main vertical degree control of the piles is also made.When the pile length is less than 70m,the suggested value of the vertical degree control is less than 1.0%;When the pile length is greater than 70m, it is less than 0.5%.Based on it, the corresponding vertical degree control of the large diameter and long pile is posed in the thesis,the problems about the vertical degree of the long and large diameter bored pile during the boring process is solved scientifically under the complex marine environment and complicated geological conditions.The results can provide references to design and construction of pile foundation for the future similar project, it also offers a case for theoretical research and has a certain value of engineering application. |
