Special soil-fetching device for static triaxial compression test of soil

Abstract

The invention relates to a special soil-fetching device for a static triaxial compression test of soil, comprising an external tube of the soil-fetching device, wherein the external tube of the soil-fetching device is a framework structure; the upper end of the external tube of the soil-fetching device is connected with a joint, and the lower end of the external tube of the soil-fetching device is connected with a tubular boot; a center shaft rod of the soil-fetching device is arranged in the inner center of the external tube of the soil-fetching device; the upper end of the center shaft rod of the soil-fetching device is connected with the joint; and a plurality of sampling tubes are arranged on the center shaft rod of the soil-fetching device. The special soil-fetching device is pressedinto the soil layer at the bottom of a borehole to sample the soil in a static manner when the soil layer of a predetermined depth is drilled by a universal drilling device. After finishing sampling the soil, the special soil-fetching device is rotated at a certain angle through the drilling device so as to disconnect the soil sample in the standard sampling tubes from the lower soil layer, the special soil-fetching device is taken out from the borehole, and then the sampling tubes are unloaded, placed in a storage box and delivered to a lab; and the operation for next soil sampling can be performed by re-installing new sampling tubes. The soil sample taken out from the sampling tubes can be directly used for a test by testing personnel, thus the accuracy and success ratio of the test canbe ensured, and the working efficiency is improved.

Description

[0001] technical field [0002] The invention relates to a soil fetching device, in particular to a special soil fetching device for static triaxial compression test of soil. Background technique [0003] The static triaxial compression test of soil is a commonly used test method in indoor geotechnical tests. The purpose of the test is to determine the total shear strength parameters and effective shear strength parameters of fine-grained soil and sandy soil. Soil samples generally use four cylindrical samples. [0004] Test principle: at different constant ambient pressures (σ 3 ) under the corresponding axial pressure (σ 1 ) to shear the soil sample until it fails; then, according to the Mohr-Coulomb theory, calculate the shear strength parameters. [0005] The preparation process of the soil sample used in the test: use a drilling machine to drill into the soil layer at a predetermined depth, and take a large soil sample with a common soil extractor. The soil samples ...

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Problems solved by technology

[0006] Existing problems: The soil samples collected by ordinary soil extractors have poor sealing performance, which has a great impact on the natural moisture content and natural density of the soil samples; the vibration during the transportation to the laboratory affects the original state of the soil samples, making the The sample data is distorted; the success rate of preparing test samples in the laboratory is very low, which causes great waste in cost and construction period

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