Device for measuring air entry value of unsaturated soil

Abstract

The invention discloses a device for measuring the air entry value of unsaturated soil. The device comprises a cover plate, pressure chamber sidewalls, a pottery clay plate, a substrate, a water inlet pipe, a water pressure-free water discharge measuring pipe and a rack, wherein the cover plate, the pressure chamber sidewalls and the substrate form a closed test space; an air inlet pipeline communicated with a pressure air source is arranged on the cover plate; the pottery clay plate is fixed on the substrate; a water inlet pipeline communicated with the water inlet pipe is arranged on the central part of the substrate; a water outlet pipeline communicated with the water pressure-free water discharge measuring pipe is arranged on one side of the substrate; the water inlet pipe and the water pressure-free water discharge measuring pipe are arranged on the rack on the two sides, respectively; isometric helical line type water discharge grooves are formed in the substrate. According to the device, bubbles at the bottom of the substrate are automatically discharged along with water flow through the water discharge grooves, and errors caused by the bubbles are not counted into a measured water discharge value, so that the accuracy of a test result is ensured.

Description

technical field [0001] The invention relates to a testing device, in particular to a testing device suitable for measuring the air intake value of unsaturated soil, and belongs to the technical field of testing. Background technique [0002] The air intake value (AEV) of unsaturated soil refers to the matric suction necessary to cause the largest pore inside the soil to generate unsaturation, and it is an important parameter for dividing the soil between partially saturated (saturated) and unsaturated states. The accuracy of the air intake value has a great influence on the dehumidification scanning line whose starting point is in the high saturation area, and also plays a vital role in the design of the capillary-blocking anti-seepage layer. Therefore, the accurate determination of the air intake value of materials has become a very important task in the soil-water characteristic curve test. [0003] The pressure plate meter is one of the basic equipment for measuring the ...

AI Technical Summary

Problems solved by technology

At the same time, due to migration, air bubbles appear under the clay slab, and the air bubbles gather in the drainage pipeline, and their volume is easily read as the displacement by mistake, which affects the accuracy of the displacement test. To solve this problem, most of them currently use repeated The flushing method discharges the air bubbles, which not only makes the operation steps more cumbersome, but also increases the difficulty of the test work

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