Uplift Loads Of Pile Of Microscopic Analysis

In long-term project practice, people have discoveried that the macroscopic character of soil is controlled by micro-structure system or overall behavior. The complex physical mechanics character is reflected by the micro-structure characteristic. In this paper, pictures of micro-structure of sand are obtained by upift test of model pile which are analysised by microscope statistical system and digital picture processing technology. Quantitative and qualitative analyses of these pictures are completed then to get the variety rule of stress and strain field as well as other parameters during the progress of loading. Relationship analyses of two types of micro-structure pictures are completed which are compared with the results of macroscopic test. The conclusion indicated that the variety feacture of micro-structure is consistent with the macroscopic mechanical response feacture.Model test is an important method to analyse the mechanical character of rock and soil. It's also an necessary means to build, exam, improve the construction model of rock and soil. Simultaneously, it provides the important reference to engineering design such as ground processing, tunnel excavation and slope sustainment. The model test of this paper is zoomed according to real foundation. The continual process of the displacement of sand is captured by microscope and digital camera. Then, pictures of them is processed by MiVnt to analyse micro-structure, pellet directivity and soilbody hole of sand. The basic researches of pellet include the area of pellet, long-short axis of pellet and eccentricity. Pellet directivity research is to reveal the variety of the angle between long-axis and horizon. The varieties of these parameters are used to analyse the features of sand during the uplift process.No-marking digital picture processing technology is an suitable system for measuring the displacement of rock and soil. This system can spot the correspondence point of serial pictures according to the color of digital picture. Displacement is calculated by tracking arithmetic, while strain is computed by the concept of FEM. This paper will use this system to observe the displacement and failure process of foundation, variety model of foundation, position of shear band and the feature of shear band. Measurement and quantitative analyses is completed in order to research the feature of whole and local displacement of sand with uplife loading.Finally, the conclusion of MiVnt and no-marking displacement measurement and macro mechanical phenomenon are compared, which indicated that the variety feature of micro-sturcture of the model reflect the macroscopic mechanical character of sand. It's feasible to research the intension and displacement features of sand by observing the micro-structure of it.