Permeability Testing Experimental System for Low Permeability Clay

Abstract

The invention provides a permeability test experimental system of low-permeability clay, and belongs to the field of geotechnique clay permeability tests. The system comprises a water head supply unitcapable of supplying tiny water heads and high-pressure water heads, a sample treatment unit for clamping and pressurizing samples, a water supply and storage unit for providing percolating fluid andcollecting the fluid, a data acquiring and processing unit for acquiring and processing experimental data, and an incubator for controlling experimental environments. According to the system, the principles of variable water heads and constant water heads of the geotechnique permeability tests are combined, the modern data acquisition technology is introduced, and the test precision is effectively improved. On the aspect of scientific research, a device can provide temperatures, loads and water head differences to be used as variables, when low-permeability clay samples with different water contents are provided, the water contents can serve as variables for permeability research of the samples, and application of conversion between the constant water heads and the variable water heads can be carried out. On the aspect of engineering parameter requirements, the device can adopt the high-pressure variable water heads to test the permeability coefficient of the low-permeability clay, and the experimental time is effectively shortened.

Description

technical field [0001] The invention belongs to the field of permeability testing of geotechnical clay, and in particular relates to an experimental system for permeability testing of low-permeability clay. Background technique [0002] Soil permeability is a hydraulic characteristic of water in soil passing through the pores in soil particles under the action of gravity. It is the three major problems involved in soil engineering and soil mechanics research (strength problem, stability problem and permeability problem). ), in engineering construction and scientific research, it is often necessary to understand the permeability of soil, for example, when calculating the amount of groundwater resources, it is necessary to understand the permeability of soil in order to obtain accurate calculation results; when studying the drainage of foundation pits, it is necessary to understand Permeability of the soil in order to design a reasonable drainage scheme. [0003] For the actu...

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Problems solved by technology

[0004] At present, traditional geotechnical permeability testers focus more on sandy soil samples (coarse grains), and there are fewer testing instruments for fine-grained or powdery-grained low-permeability clay, and there are long penetration times and low accuracy of manual readings. The defect of large error; In terms of experimental environment control, traditional geotechnical permeameters do not control the experimental temperature, and use the formula ( Among them, k is the permeability coefficient, η is the viscosity of water, and T is the temperature) for conversion. This calculation method only considers the influence of temperature on the properties (viscosity) of water, but does not consider the influence of temperature changes on the properties of soil. This will undoubtedly increase the error of the experimental results

Therefore, the current permeation device cannot meet the needs of high-precision scientific research, and it takes a long time to obtain the permeability parameters required by the project.

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