Prestressed Anchor (cable), Anti-slide Pile Embedded Depth Research

The anti-slide pile with prestress anchor is invented in 1980s, as one of new type structure, it is applied widely to treat landslide, for the reasonableness of its stress, more money invested is saved. Despite this, the research level of the pile design is in a backward state, it is still difficult to define the built-in depth of pile accurately. At present, the built-in depth of pile is designed by means of experience with the method of their owns, thus, any problem may be leaded for it. Failure case may occur for the radical design of built-in depth, vice versa.It is a balance system that the anti-slide pile is exerted by three kinds of force, they are the tensile force of anchor, the thrust of sliding mass, the resistance of soil and rock. In the meantime, It is a equilibrium between the moment generated by thrust and the moment generated by the resistance, around the anchor spot. The built-in depth of anti-slide pile can be get after ascertaining of the distribution and value of the thrust and the resistance. The thrust of sliding mass has been researched for long time, and its result is good. In the thesis, the resistance of soil and rock is researched by means of three methods of the theory of limit equilibrium, they are the method of passive earth pressure, the method of slip line and the method of elastic wedge.In the thesis, three computation module of each method are presented with their owns hypothesis. This three method are applied to solve the same question, and the yield criteria is same as each other, so the same result should be get at last, while, the solution value of the method of elastic wedge is less than the other two methods, the reason is that the physics equation is submitted in the method of elastic wedge. The built-in depth solved by the method of the elastic wedge is the upper limit, and the depth solved by the fist two methods is lower limit, so the last method is recommended to design the practical engineering. Because the Mohr-Coulomb yield criteria is submitted in the course of solving resistance, the value of the built-in depth generated by these method are safe. Compare with the traditional empirical depth, 1/2 to 1/3 of length of the pile, much built-in depth is decreased.The proper model test is selected to verify the conclusion made by the thesis, it is showed that the computation module presented is correct, the built-in depth solved by the method given in the thesis is reasonable and economical, it is one method of comparative high worth.