Study On The Whole Process Pressure Measurement And Bearing Capacity Characteristics Of Static Pressure Tubal Pile

In recent years, piles especially jacked plies are widely used in China, but the theory of static pressure tubal pile was not well understood. A series of questions, such as lateral pressure and frictional resistance, are in great need of solving. Experimental study is an important method to solve the problem.In this paper, a semi-analytical -numerical method based on theory of plate and shell was put forward, combined with the penetration test and static loading test, we can correctly transform the strains of pile into lateral pressure and frictional resistance. This method can make up for the traditional methods and we can obtain the stress acting during the penetration and static loading. Based on this the main research is as follows:A semi-analytical -numerical method based on theory of plate and shell was put forward, that is to inverse calculate the lateral pressure and frictional resistance of jacked plies by the strains. The principle of inverse calculation theory was expounded in detail at first. Using the finite element analysis software ANSYS, the static analysis of static pressure tubal pile was carried out. The inverse calculation was used in this finite element analysis and obtained one correct results.Using organic glass pipe as model pile, the penetration test and static loading test were carried out in self-made sandbox. Based on the test dates, lateral pressure and frictional resistance were calculated by the inverse calculation method.This paper analyzes the change law of lateral pressure and frictional resistance in the process of penetration and static loading, and shows the differences between measured values and theoretical values. The coefficient of earth pressure was calculated in the two processes and compared with the three theoretical coefficient of earth pressure.Based on static loading test, the change curve of pile shaft force and the relationship curve of pile top axial load and pile top settlement were given in this paper. At the same time the change law of soil around pile was measured when the pile top axial load increased. Also a timeliness analysis of pile bearing capacity in sand was carried out.The method proposed in this paper can correctly calculate the stress distribution of static pressing tube pile in real-time and the load transfer behavior and the bearing capacity characteristics of static pressing tube pile were obtained, providing the powerful support for mechanical property analysis and practical engineering testing of jacked pile.