A Practical Method For Calculation Of Settlements Of Pile Group Foundations

Domestic and foreign scholars have been given an insight into the pile foundation, but whether it is the pile settlement theory, or in engineering practice, there are many problems and shortcomings, and it should be further improved and developed. As we all known, the calculation of the settlement are important processes in pile foundation design. The bearing capacity and settlement of the vertical pile foundation are the two most important factors in the design of the pile design. At the same time, because the theoretical calculation of the single pile settlement is the basis of establishing settlement theory of pile foundations, and the theoretical calculation of the single pile settlement is joint connect with the settlement theory of pile foundations , thus the analysis of pile settlement calculation has become a necessary process of pile group design. There are many factors affect the pile settlement, including the pile length, pile layout conditions, soil geology, soil pile and the relative displacement and the load duration, etc. Some of these factors are uncertainty, some are difficult to identify fully. This paper reviews and summarizes the settlement analysis of pile foundation under the vertical load, the basic theory of finite element and introduces software ABAQUS briefly.Then, the paper considers the complicated properties of soil and the influence of the pile groups characteristics under the vertical loads in the pile-soil interaction, such as generation of the modified base in simplifying the pier pile model. How to find the composite foundation model E of soil and pile is a major difficulty of this article, we use area-weighted composite modulus formula, and considering the length of pile, pile-side soil properties on the composite modulus, the use of composite foundation mechanism of pile bearing area ratio of composite modulus correction formula can obtain the approximation of the composite modulus. After the obtained composite modulus E , then, combine with the pier-based to replace the medium on behalf of the pier base specification method (compression modulus of pile), and use this method in a instance to calculate the settlement of pile groups to compare with the method in specification, and then use the finite element software ABAQUS to carry on the finite element simulation, four methods will obtain four groups of settlement data and compare all results to find which method is the most closer to the actual settlement, then, verify the correctness and feasibility of the method used in the text.