Calculating Method Research And In-situ Test Analysis On Laterally Bearing Characteristic Of Immersed Tube Filling Pile

In recent years, with the continuous improvement of the construction technology, many kinds of the evolved immersed tube filling pile have better quality, higher construction speed, and lower cost. They have been used in multi-floor building and some higher buildings. The higher the building is, the more it demands of the immersed tube filling pile. It requires better loading capacity not only in the aspect of the vertical load, but also in the aspect of the lateral load. However, most of such piles are erect, so taking the laterally bearing capacity of piles into consideration is imperative under the situation.In this thesis, based on in-situ lateral load test, immersed tube filling pile was further researched, empasis of which was laid on its laterally bearing characteristic and calculating method and research approaches and instruments such as in-situ test, statistic analysis, numerical simulation and example verification were applied. The primary coverage of research was detailed as follow:Firstly, I analyzed the current internal and external research situation of the properties of the laterally loaded pile, studied the laterally loaded pile's constructive and destructive properties in the course of its bearing load, and summarized various calculating methods concerning the laterally loaded piles, emphasis of which was laid on analyzing and contrasting the advantages and disadvantages of the major methods used currently.Afterward, combining with the in-situ laterally loading test of the immersed tube filling pile, I analyzed and summarized the characteristic, design, laterally bearing properties, and made a meticulous analysis on the original position result, thus working out a law by which the pile bearing lateral weight works. And then some popular linear-elastic-foundation-react methods were applied to carry on theoretical calculation of laterally bearing properties of the test piles.Having analyzed the in-situ lateral load test figures and regressively fit them by using MATLAB software, I proposed a new method for calculating the laterally bearing characteristic of the immersed tube filling pile. This new method which belongs to the category of non-linear elastic foundation react method is available for the calculation of the elastic free-head pile. We'll see from the non-linear differential equation that the foundation reacting force by the side of the pile varies in a linearity way with depth, and also in a linearity way with one third displacement. On the basis of the sufficient consideration of the elders'work and combining with the test foundation of the new method discussed above, I put forward to establish standard pile in order to apply the similarity theory to calculate the practical pile. And for the non-linear differential equation has no analytic solution, in this thesis the finite differential program FLAC3D was adopted to carry on numerical simulating calculation. With the parameters of standard pile under new method fixed and the standard pile's load and displacement sheet established, the calculating procedure of the new method was finally accomplished.Lastly, after contrasting the in-situ test figures with the calculating results by new method, it was testified that the new method is practical and operable. Moreover, on the basis of the numerical simulation of the standard pile, I also discussed how the laterally bearing properties of the immersed tube filling pile would be influenced when some factors such as its length, diameter, pile body bending rigidity, vertical load on pile top change.This research completed in-situ test study and theoretical analysis on laterally bearing characteristic of immersed tube filling pile, elicited the law of foundation reacting force varying with depth and displacement, proposed a new calculating method on the laterally bearing characteristic which had been preliminary demonstrated and applied in this thesis.