Tubular pile sinking simulation test device and method under gradient confining pressure

Abstract

The invention discloses a tubular pile sinking simulation test device and method under gradient confining pressure. The test device comprises a counter-force supporting frame, a loading device, a wave velocity testing device, a model tubular pile and a confining pressure simulation assembly. According to the confining pressure simulation assembly, a model cylinder is formed by stacking a plurality of confining pressure annular layers and hoops a soil sample formed through layered filling by means of a membrane bearing cylinder, and the effect of water pressure is utilized for pressurizing a soil column piecewise. The model tubular pile is composed of an inner sleeve, an outer sleeve, a super kamei deadening felt, a pile inner sleeve, a top core screw and a pile end stop block. The inner sleeve and the outer sleeve are coaxially attached, an excitation element and a receiving element are arranged in a pair along the inner surface and the outer surface of the tubular pile at different heights, pile core soil and pile side soil are subjected to shear wave velocity measurement, and the pile inner sleeve is used for protecting a bending element in the pile driving process and assisting the top core screw to control the height of the pile core soil. According to the tubular pile sinking simulation test device and method under the gradient confining pressure, a load transmission rule in the driving process of the open-ended tubular pile and synchronous dynamic testing in the soil body property evolution process are achieved, the confining pressure is sectionally controllable, loading is convenient and fast, and the measuring precision is high.

Description

technical field [0001] The invention relates to a pile sinking simulation test device and method for pipe piles under gradient confining pressure, and belongs to the technical field of pile foundations in the field of construction engineering. Background technique [0002] With the continuous development of housing construction, transportation, port, petroleum and wind power engineering construction, pipe piles are increasingly used in construction engineering and offshore engineering. During the penetration process of the open pipe pile, the soil particles near the pile body will move and squeeze each other, and at the same time, the soil mass at the pile end will pour into the pipe pile to form a soil plug, that is, there will be a soil plug effect and a soil extrusion effect. As the penetration depth increases, the lateral stress of the soil increases, the frictional resistance outside the pile and inside the pile gradually increases, and more and more soil is extruded in...

AI Technical Summary

Problems solved by technology

However, none of the above-mentioned inventions can simulate the in-situ stress level and distribution characteristics of natural soil under the action of self-weight, and there is a lack of tests on the dynamic evolution of the soil around the pile and the soil in the pile core.

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