The Indoor Model Tests And Numerical Analysis Of Single Pile Under Low Cycle Reciprocating Lateral Load

In the traditional civil engineering, the foundation was mainly used to bear the vertical load of the building. With the continuous development of society, the rapid increase of population, high-rise buildings become an important symbol of modern civilization, pile foundation has also been rapidly developed, the characteristics of lateral load is more and more get the attention of many scholars, especially under seismic load. Through the indoor model tests,displacement-load hysteresis curves of single pile and pile with cap under low cycle reciprocating lateral load and the pile cracks of pile with cap are analyzed in this thesis. On the basis of tests, finite the element software ABAQUS is used to establish the entity models and analyze deeply the pile-soil interaction system.The main conclusion are summarized as follows:(1)From the views of experiment, theory and finite element analysis, author summarizes the current research status of pile foundation under lateral load,compiles the related data and introduces the content in the thesis.(2)The failure mechanism of different piles under lateral load is summarized, the indoor model tests under low cycle reciprocating lateral load are discussed and summarized. The results show cap can effectively improve the energy dissipation and vibration resistance of pile foundation. The cracks of pile with cap are noted and analyzed, then the most prone to cracking position is found out.(3)On the basis of tests results, the entity models is established by use of FEA software ABAQUS. The displacement-load curves for reference points getting from FEA agree well with those getting from the indoor model tests to verify the feasibility of using finite element simulation.(4)By using finite element simulation, contrast displacement-load hysteresis curves and viscous damping coefficients of single pile and pile with cap are contrasted and the results verify the role(2). In the bending moment curves of finite element simulation, the maximum value is still at the connection location of pile and cap. By comparing the displacement of pile body, it can be found that the cap reduces the disturbance of the underlying soil. The soil resistance is pick up by analyzing the soil around the pile and under the cap.From PEEQ clouds, the damage area of soil can be found. Some valuable conclusions are drawn out, which may provide a theory support to the design and construction of pile foundation under low cycle reciprocating lateral load.