Permeameter for metering unsaturated coefficient of permeability of high-compacted bentonite and metering system

Abstract

The invention relates to a permeameter for metering an unsaturated coefficient of permeability of high-compacted bentonite and a metering system. The permeameter comprises a thick-walled sample sleeve, a water entry end cover block, a water exit end cover block and an attachment, wherein the thick-walled sample sleeve, the water entry end cover block and the water exit end cover block are made from a Teflon material, and the attachment is composed of the thick-walled sample sleeve, the water entry end cover block, the water exit end cover block and add-ons. The metering system comprises a nuclear magnetic resonance analyzer, a sustained water injection mechanism and the permeameter, wherein during testing, the permeameter loaded with a test soil sample is placed in a radio-frequency coil of the nuclear magnetic resonance analyzer, the sustained water injection mechanism is connected with a water inlet hole, and thus, permeation water pressure is provided after air of a water injectionend is exhausted. Compared with the prior art, the permeameter and the metering system have the advantages that the permeameter and the metering system adapt to technical requirements on measurement of the unsaturated coefficient of permeability of the high-compacted bentonite by adopting a nuclear magnetic resonance technique, including being capable of bearing a relatively large expansion forceand maintaining the volume of a bentonite sample during water seepage constant; materials such as Teflon and quartz sand are adopted, so that the influence on nuclear magnetic signals caused by the device can be avoided.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering, and relates to a permeameter and a measuring system for measuring the unsaturated permeability coefficient of high-compacted bentonite. Background technique [0002] Unsaturated soils are widely distributed in nature, and many engineering problems involve the seepage analysis of unsaturated soils. Laboratories often use the instantaneous cross-section method to measure the permeability coefficient of unsaturated soil. The difficulty of the instantaneous section method lies in the determination of the water content (suction) of the section mass. With the rapid development and wide application of nuclear magnetic resonance technology, nuclear magnetic resonance technology has gradually been applied to the measurement of unsaturated soil permeability technology. It is a new method that can quickly and non-destructively detect the permeability coefficient of unsaturated soil samples. Seepage...

AI Technical Summary

Problems solved by technology

Traditional unsaturated soil permeameters are mostly made of ferromagnetic metal materials (stainless steel, etc.), but because ferromagnetic materials will affect the identification and acquisition of NMR signals, they are not suitable for NMR technology to measure the unsaturated permeability coefficient of high-compact bentonite the test

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