Vacuum negative pressure static test pile technical method

A vacuum negative pressure static test pile technical method detects the quality problem of a pile foundation. The seepage problem of liquid or a liquid and gas mixture in a single-layer or multi-layer unsaturated soil mass is solved by applying finite difference and finite element numerical methods and other numerical methods through a modeling method. Buckling failure of the soil mass caused by flowing soil, piping and the like is avoid through a pore fluid penetration technology. The concrete operation method comprises the steps that firstly, a soft sealing layer covers the upper portion of a test pile to form a sealed space, the soft sealing layer is a seepage-proofing layer, the seepage-proofing layer reserves certain permeability, and the sealed space is a rigid platform; secondly, in the experiment, a vacuum air pump or a jet pump pumps out air in the sealed space, the sealed space becomes vacuum, and the vacuum degree in the sealed space is above 85%; thirdly, external atmospheric pressure generates huge pressure on the platform of the sealed space and the huge pressure serves as counter force needed for test pile loading; and finally, after the experiment is completed, only air is put into the sealed space step by step. The project quality and progress are ensured.