A sample preparation device, sample preparation method and permeability coefficient determination method of a sand-soil contact surface sample

Abstract

The invention discloses a sample preparation device and a sample preparation method for a sand-soil contact surface test sample as well as an osmotic coefficient determination method. The sample preparation device mainly comprises an outer barrel and an inner barrel which are coaxially arranged; the part between the inner barrel and the outer barrel is filled with sand by layers and is impacted; the inner barrel is slowly upwards lifted to a certain height and then is fixed; a certain amount of clay is weighed and is poured into the inner barrel; the clay is impacted to a pre-set height and then the inner barrel is slowly upwards lifted; the clay is poured and impacted, and the step is repeated for multiple times to reach a pre-set sample height; and the sample preparation device is detached and a test sample is taken out; the sand adhered to the surface of the test sample is slightly brushed off by a soft hairbrush, namely the sand-soil contact surface cylindrical test sample which is tightly filled with the sand at the periphery can be obtained. Then the thickness and the sand content of a sand-soil contact surface are measured by adopting a parallel test. Furthermore, a flexible wall test can be utilized and water in each sand-soil contact surface test sample permeates along two paths of the middle clay and the sand-soil contact surface; and the osmotic coefficient of the sand-soil contact surface can be calculated according to a Darcy law.

Description

technical field [0001] The invention relates to the field of geotechnical engineering geotechnical tests, in particular to a sample preparation device, a sample preparation method and a permeability coefficient measurement method for a sand-soil contact surface sample. Background technique [0002] In many cases in geotechnical engineering, it is necessary to consider the interface between two materials, such as face plate and gravel cushion in face rockfill dam, core wall soil material and filter material, dam body soil material and bedrock. At present, the research on the contact surface mainly focuses on the strength and deformation, including experimental research and numerical analysis. Usually, direct shear test, simple shear test, and ring shear test are used to carry out stress-strain test research on the contact surface. In the calculation, it is used to simulate the deformation of the contact surface, and the commonly used one is the Goodman unit. In engineering, ...

AI Technical Summary

Problems solved by technology

However, the contact surface of sand cushion and expansive soil is a contact surface formed by two flexible materials. At present, there is no good test method at home and abroad to study the permeability of sand-soil contact surface.

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