Sample preparation device and sample preparation method for expansive soil in liquid limit state

Abstract

The invention relates to a sample preparation device and a sample preparation method for expansive soil in a liquid limit state. The sample preparation device comprises a cylindrical sleeve, the sleeve comprises a plurality of side plates, the cross sections of the side plates are arc-shaped, and a plurality of drainage holes are formed in the side walls of the side plates and are arranged at equal intervals in the length direction of the side plates. The upper end and the lower end of the sleeve are sleeved with lantern rings, internal threads are arranged on the inner walls of the lantern rings, and external threads matched with the internal threads are arranged at the ends of the side plates. By adopting the sample preparation device for expansive soil in a liquid limit state, the layering phenomenon of a cylindrical sample prepared by a layered sample hitting method can be solved, it is ensured that the interior of a prepared cylindrical sample of expansive soil is uniform and consistent and the sample does not have a weak surface, the discreteness of a parallel test result is reduced, and the physical and mechanical properties of expansive soil can be reflected more accurately. The sample preparation device for expansive soil in a liquid limit state is simple and convenient to mount and dismount, the three side plates cannot be misplaced during mounting, and the implementation effect is good.

Description

technical field [0001] The invention relates to a sample preparation device and a sample preparation method under the liquid limit state of expansive soil, belonging to the technical field of geotechnical tests. Background technique [0002] The preparation of cylindrical samples under the liquid limit state of expansive soil can make the prepared samples achieve uniformity and consistency, make the error of test results such as compressive strength test small, and determine the accurate physical and mechanical properties of expansive soil. At present, the domestic geotechnical test method standards related to the expansive soil compressive strength test and other geotechnical tests use the layered sample method, and most of the samples of the layered sample method appear to be delaminated during the unconfined compressive strength test. ——The upper sample is not damaged, but the lower layer has been split, and there is a fault in the middle. The reason may be that the conn...

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Problems solved by technology

The reason may be that the connection between layers is not dense, the connection force between layers is much lower than the shear strength of expansive soil, and the horizontal force generated before or during the vertical failure of the sample exceeds that between layers. The connecting force caused by the fault phenomenon in the middle of the sample, the discreteness of the parallel test results is large, and the physical and mechanical properties of expansive soil cannot be accurately reflected

After reviewing relevant domestic and foreign literature, so far there is still no good way to prepare expansive soil cylindrical unconfined compressive strength samples.

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