Studies On The Load Bearing Behavior Of Large Diameter Tubular Pile And Its Application Research In The Seawall Structure

Tubular pile has many advantages, such as simple construction, high bearing capacity, good economics, etc. So it has a wide range of application in the excavation engineering, road engineering, marine engineering and other fields. As a new type of pile, the design theory of Tubular pile lags in the practice. And, the further research is needed due to lack of effective and simple calculating methods about the evaluation of its bearing capacity in soft soil foundation. But, at the same time, the application of tubular pile in the seawall structure is one of the research hotspots. There is no criterion of design and references to the structural design of tubular pile seawall under the wave loading at present. Therefore, this paper will study the bearing behavior of tubular pile in the soft soil foundation, combining the actual engineering. The main contents and conclusions of the paper are as follows:1. The vertical bearing capacity of tubular pile based on load transfer function was researched. By using different load transfer functions for the soil around the tubular pile and considering the sharing load of soil core and the internal friction resistance of tubular pile, a set of analytical equations for the axial load-settlement curve of tubular pile have been deduced. The distribution equations of axial force and friction along pile can be gotten. At last, with a actual engineering, we can verify the correctness of the formula. The results show that the set of formula has good value in use.2. With the finite element method, this paper studies the bearing behavior of tubular pile under vertical or horizontal loads. Compared the result of finite element analysis with field test results, the application of the FEM analysis on the study of tubular pile bearing behavior is reliable under the vertical loading. Meanwhile compared the result of equal section solid pile with tubular pile by FEM analysis, the results show that tubular pile has great advantage in resistance to horizontal loads. At last, this paper analyzes the bearing behaviors of the three typical tubular pile foundation in Hangzhou region and gets some practical conclusions.3. By using stiffness equivalent method, this structure is simplified into plain strain problem. Horizontal load is the main load acting on the structure Hence through numerical analysis, the horizontal properties of this kind of seawall are investigated, Different effects on its behavior are studied, such as pile spacing, row spacing, pile stiffness, connecting beam stiffness, penetration depth, the location of connecting beam. Useful conclusions are helpful for its design and popularization.