A Method To Calculate The Settlement Of Pile Foundation Based On The In-Situ Vertical Static Load Test On Single Pile

Pile foundation, as one of important structures in civil engineering, has been widely used. The settlement of pile foundation, which impacts directly on the safety, stability and economy of the project, is the key target in the design procedure. It remains to be hard to determine the settlement accurately due to numerous influence factors, although there has being a large amount of researches.The in-situ static vertical load test on single pile, utilized commonly in engineering, well reflects characteristics of the pile, soil and pile-soil interaction. A new method is provided to calculation through introducing the test.(1) For the elevated capping pile foundation, the upper load is assumed by piles. Load on a pile could cause the settlement of both itself and other piles. Thus the settlement of a pile can be divided into two parts. The first part, caused by load on pile itself, can be determined by load-settlement curve, meanwhile the second part, caused by other piles, can be solved by Mindlin solution.(2) The calculation theory of low capping pile foundation is similar with the elevated. Besides, the settlement of pile, caused by soil pressure under the pile cap, and the deformation between the cap and soil are also considered in calculation through Boussinesq solution.(3) Frictional force in side-pile, stress at pile end and deformation modulus of soil layer can be calculated through the results of the in-situ static vertical load test on single pile.(4) Loads on the piles and soil pressure under the pile cap should satisfy the force equilibrium equation, settlement of the pile and soil under the pile cap should satisfy deformation compatibility condition. The trial method and the iterative method can be used to solve those equations.According to the above theory, the corresponding calculation formulas are established as well as the software by Matlab. Two examples are tested and the result shows a preferable goodness of fit between the data of calculation and measurement, which proving the rationality of this method.