Testing And Analysis Of Pile Bearing Capacity And The System Of Pile-Soil Interaction

Pile foundations are widely applied in bridge construction. The existing calculation theory of the vertical bearing capacity of piles contrasts with it's practical loading characteristics, and the further investigations about it will be performed. Therefore the investigation in pile loading capability and interactive mechanism of soil and pile is very important and urgent.(1)It outlines factors influencing loading capability, method to determine loading capability and present research progress in this field. It also makes a systematic analysis of the characteristics of present pile examination methods and sums the application conditions of these methods. As to different piles, properly corresponding construction technique and examination method should be applied. For the important structure or super loading-capability pile foundations which loading test must be carried, we can adopt the Self-Balanced Loading Test Method, and introduce the example of it. However, strict quality control of pile construction is the guarantee of good quality of pile.(2)It makes thorough discussion of interactive working mechanism of soil and pile and further study of relation curve of load-sink, axis pressure distribution with its respective depth, concerning parameters of soil, the ultimate resistant capability and determination of reaction force, sink residue and the influence of length-diameter ratio to ultimate resistant capability etc... It proposes that the loading capability is not only related with soil property, pile diameter, length-diameter ratio, ratio of inserted rock length to diameter and material property of pile, and also closely related with bore quality, rough degree of bore wall and thickness of sink residue etc... At the same time, it analyzes the method that determines the loading capability of single pile.(3)The application of radial damping in the high strain dynamic exploration had brought investigators attention on field of dynamic exploration. The soil parameters in dynamic resistance forma of this kind of model such as shear modulus, density of soil, Poisson ratio and resistivity coefficient can be obtained by the routine soil test and the sympathetic vibration pole test therapeutics. Using the method, the soil parameters could be considered in the process of pile sinking.(4)The calculation model of pile-soil interaction and its impact on determining the bearing capacity of piles are analyzed. The calculated values of the bearing capacity of piles are compared with the associated experimental results.(5) Combination with a certain project practice, the test methods and the theoretical calculating formulas in this paper are applied in the practical project. Moreover, based on above all, the measures of elevating the bearing capacity of piles and the strengthening measures of piles are proposed in the thesis, which can agree with the practical project.