Anisotropy measurement device and measurement method of hydraulic characteristic of unsaturated soil body

Abstract

The invention provides an anisotropy measurement device of the hydraulic characteristic of an unsaturated soil body. The anisotropy measurement device comprises a weighing device, a soil sample container and soil water potential measurement instruments, wherein the soil sample container is placed on the weighing device; soil water potential measurement instrument mounting holes are formed in the soil sample container; the soil water potential measurement instruments are mounted in the soil water potential measurement instrument mounting holes; the soil sample container is provided with a top sealing plate and a lateral sealing plate; the top sealing plate and the lateral sealing plate are used for opening or closing the soil sample container. According to the invention, a soil-water characteristic curve and an unsaturated permeability coefficient of the same soil sample measurement soil body are determined by measuring suction force in different positions and the flow of an evaporation surface; an unsaturated hydraulic characteristic parameter is measured via a simple evaporation method, so that the test time is shortened; unsaturated hydraulic characteristic parameters in vertical and horizontal directions of the soil body can be measured respectively by changing a direction of the evaporation surface. The invention further discloses a measurement method.

Description

technical field [0001] The invention relates to a measuring device and a measuring method for the anisotropy of hydraulic properties of unsaturated soil. Background technique [0002] The granular structure characteristics of soil determine the generation of soil anisotropy, especially in layered compacted soil. In layered compacted soil, the mesoscopic structure of the soil is layered, resulting in extremely serious anisotropy of unsaturated hydraulic parameters. The unsaturated hydraulic characteristic parameters include the soil-water characteristic curve and the unsaturated permeability coefficient of the soil. The difference in the unsaturated hydraulic characteristic parameters in the vertical and horizontal directions of the soil is one of the main reasons for the inaccurate prediction of seepage in the unsaturated soil. This problem generally exists in agriculture, forestry, soil science, civil engineering and other disciplines. Especially in civil engineering, un...

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Problems solved by technology

[0003] Existing research is more about the measurement of unsaturated permeability coefficient. Chinese patent application CN201210196089.4 proposes a device for measuring the permeability coefficient of unsaturated soil. Chinese patent application CN20130205267.X also proposes the measurement of hydraulic characteristic parameters of coarse-grained soil. , but neither of these two methods can measure the anisotropy of the hydraulic characteristic parameters of unsaturated soil

[0004] Chinese patent application 201210530675.8 proposes a measurement of layered coarse-grained soil anisotropy, but it cannot measure the soil-water characteristic curve and hydraulic coefficient equation of unsaturated soil, let alone measure the anisotropy of hydraulic characteristic parameters of unsaturated soil

In this technique, the sampling is complicated, and it is easy to disturb the sampled soil, which affects the measurement accuracy, and the measured permeability coefficient is only in the saturated state, and the water-soil characteristic curve and permeability coefficient of unsaturated soil cannot be measured.

[0006] At present, there is no research involving the soil-water characteristic curve and the anisotropy of the unsaturated permeability coefficient of the soil, and there is no equipment for directly measuring the soil-water characteristic curve and the anisotropy of the unsaturated permeability coefficient.

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