Characteristics Of Fin Piles Under Lateral Loads

With the high-speed development of economy and technology, shortage of resources and environmental problems highlighted increasingly, how to efficient use of limited resources and space become the focus of attention, for building engineers, this problem is also what they think. Now, increasing the height of the building, structure designers put forward the higher request, pile foundation construction widely used because of its excellent load-bearing performance. In recent years, the rapid rise of offshore wind power industry, because of the complicated environmental factors make offshore wind farm construction conditions and load conditions of single pile is more complex, the research focus is from the vertical bearing capacity of pile foundation design of the control to effectively control the horizontal displacement of pile foundation, in order to effectively resist horizontal thrust, adopts the method of fins in pile, namely "fin pile". As a new type of pile foundation of offshore wind, its light weight, simple structure, and the fins can significantly improve the level of its bearing capacity, thus the fin pile has the promotion and development of important significant.Mechanical characteristics of the pile foundation of the fan on the sea, it is necessary for large diameter thin-walled steel tube fin pile under horizontal load structure of an in-depth and systematic research, theoretical analysis and numerical analysis for structural design of offshore wind farms in China to provide theoretical basis and technical reserves.This paper using the large finite element software ANSYS to fin pile under horizontal load properties of bearing capacity are conducted in-depth study.This paper mainly study from several aspects:(1) Soil based on the large general finite element software ANSYS, the follow Drucker-Prager yield criterion completely elastoplastic constitutive model of pile body and the shell element to simulate fins used in place of the entity of pile, by establishing a system of 3D finite element model of the fin pile foundation is analyzed by horizontal loads.(2) This paper analyzes P-Y curve (load-displacement curve of pile head) of the fin pile(single pile) under limit load, considering the fin length, fin width, pile length and pile diameter, and fins position and the direction of multiple sets of load change parameters for the horizontal bearing capacity of the fin pile. And at the same time under the influence factors such as different horizontal loads, the soil elastic modulus, poisson’s ratio of soil, the friction Angle of soil, soil cohesive force, the fin piles and bare along pile body displacement and bending moment distribution is discussed. The fin pile is obtained compared with bare pile in resisting horizontal direction of bearing capacity has increased significantly, and the influence of different factors for fin pile horizontal load ability to influence the degree of different sizes, including fin length to its impact is bigger.(3) Because in actual engineering, offshore wind power base is generally in the form of group piles, so the article also analyzes the 1×2 pile structure under horizontal load force mechanism, and mainly compared the pile spacing, pile length and the effects of the friction Angle of soil on pile group efficiency. Results show that the efficiency of the front fin pile were greater than the back fin pile, and increasing the fin pile spacing can effectively improve the efficiency of the pile group, pile length within a certain range for improving the efficiency of pile group effect is obvious, but increases to a certain degree, improve the effect is not obvious.