Time domain reflection unsaturated permeameter and method for measuring unsaturated permeability coefficient

Abstract

The invention relates to a time domain reflection unsaturated permeameter. The center of a barrel cap (11) is provided with an air outlet (1); the joint of the barrel cap (11) and a barrel wall (8) is sealed by a first rubber ring (2), and the joint of a base (10) and the barrel wall (8) is sealed by a second rubber ring (6); and 5 buried waveguides (3) are arranged at equal intervals in the barrel wall (8), a soil sample in the barrel wall (8) is isolated from the base (10) by porous stones (4), and the positions on the base, corresponding to the porous stones, are respectively provided with a water inlet (7) and a water outlet (5). The invention also provides a method for measuring the unsaturated permeability coefficient of a soil body. The method uses a time domain reflection probe to measure the water content of the soil body in the fixed positions and solves the unsaturated permeability coefficient of the measured medium by making use of the beforehand-measured soil-water characteristic curve of the measured soil body and finally using the instant section method. The invention can be used for measuring the unsaturated permeability coefficient of different soil samples (undisturbed or remolded) and improves the accuracy.

Description

technical field [0001] The invention belongs to the field of civil engineering, and in particular relates to a novel geotechnical experimental equipment and an experimental method for geotechnical engineering test research. Background technique [0002] With the rapid development of civil engineering, agriculture and other related fields, the unsaturated soil permeability coefficient has been paid more and more attention. In the stability of foundation pits and slopes, the analysis of water seepage in soil, the migration of water and substances, and the nuclear waste How to obtain the unsaturated permeability coefficient of soil has become a difficult problem to be solved urgently in engineering construction and related fields. However, in current engineering practice at home and abroad, the method of predicting the unsaturated soil permeability coefficient is mainly adopted, such as determining the unsaturated permeability coefficient of soil samples and the soil-water char...

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Problems solved by technology

However, in current engineering practice at home and abroad, the method of predicting the unsaturated soil permeability coefficient is mainly adopted, such as determining the unsaturated permeability coefficient of soil samples and the soil-water characteristic curve through experiments, and using a mathematical model to fit the soil-water characteristic curve. Then according to the permeability coefficient analysis technology, the permeability coefficient function is finally calculated. Many scholars have found that the predicted value and the measured value have a large difference, which will inevitably lead to incorrect analysis of engineering problems and bring greater misleading to engineering practice.

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