Study On The Whole Process Pile Circumferential Stress Variation Characteristics Of Static Pressure Tubal Pile

The application of pile foundation in many forms of practical engineering in the pipe, using static pressure method construction technology of forming has the quality of pile body is easy to check and ensure the engineering cost, relatively low, and has the advantages of good stability, small and uniform settlement, bearing capacity, low settlement rate and so on, so that it became the foundation form in modern engineering system. However, current research on the resistance of pile sinking pipe pile construction is not mature, and the pile sinking mechanism of pile and its bearing capacity of relative to the engineering application are relatively backward. Moreover, research in each aspect, the single pile penetration and static load test is a test method for evaluation of pile construction quality is good or not essential, the research also appears especially important. Compared to the pile foundation test, repeatability, indoor model test with the test condition and easy to control, and in the economy and convenient compared with the field test have great advantages, has become the important means to study the pile foundation pile and bearing mechanism.For the analysis of static pile in pile sinking pile body stress changes related to explore, it needs make research on the mechanism of pile foundation static pressure method construction in pile and static loading process. In this paper, through the study of previous research methods of the scholars and the relevant results, it is necessary to learn from the model test of static pressure pile experience. Then use this new method of a pile foundation test to measure the test of pile stress strain data, which make up the disadvantages in traditional test. This paper mainly explains the following several aspects of research work:(1) This paper use a model pile test method to try, through the pipe wall pasting temperature self compensation strain gauges to test pressure, and then use it to calculate pile under pressure, static load process, a numerical analysis method of friction resistance, tip resistance and lateral pressure. Use the reliability and the modeling theory and finite element analysis software to verify the test method, the test application performance in good matching.(2) The tests use a self-designed multifunctional static pile pressing device, which comprises a model pile device, loading device, data acquisition system, a complete set of equipment. And relying on structure, rock and soil mechanics laboratory, test device in test run in perfect. Test equipment runs well, and provides the experimental basis and a good environment for indoor model test.(3) Based on the static pressure pile in a test equipment, this paper makes a series of model tests. It includes the pile penetration test and static load test of two parts. Strain through information collection system whole measure and record the model pile in sandy soil during pile driving and static loading process of stress and strain change, change rules of pile driving and static loading process of pile lateral pressure and friction are studied. And analyzes the relations between lateral pressure and friction, pile sinking mechanism of preliminary inquiry of static pressure pipe.