Test device for rapidly testing soil strength and permeability coefficient by simulating freeze-thaw cycle

Abstract

The invention discloses a test device for rapidly testing soil strength and permeability coefficient by simulating a freeze-thaw cycle, and relates to the technical field of soil mechanics and geotechnical engineering. The test device comprises a box body and a sample box, wherein the sample box is arranged inside the box body; and the test device further comprises a measurement system used for measuring various physical and mechanical parameters of soil, a freeze-thaw cycle system used for providing temperature control for a freeze-thaw process of a soil sample, and a displacement control system used for horizontal and vertical precise movement of each sensor. The test device has the benefits that a micro-static probe can measure the penetration resistance of a soil taper tip, and a crossshear plate can measure the undrained shear strength and shear modulus of the soil sample; and by analyzing the relationship between the undrained shear strength and the shear modulus of a specific soft soil sample through tests, the most simple and feasible solution for calculating the shear strength of the on-site soil by a static penetration test can be provided.

Description

technical field [0001] The invention relates to the technical fields of soil mechanics and geotechnical engineering, in particular to a test device for quickly testing soil strength and permeability coefficient by simulating freeze-thaw cycles. Background technique [0002] my country is a country where expansive soils are widely distributed. A large number of construction sites are located in expansive soil distribution areas. After expansive soils are frozen at low temperature and melted at room temperature, various parameters of the soil will change greatly. [0003] In the past, when testing the basic strength and deformation characteristics of the soil, only a single index of the soil can be tested each time, such as the compressive modulus of the soil, the undrained strength of the clay, the side friction resistance, the shear strength or the shear modulus. etc. There is no test equipment for the comprehensive measurement of multiple parameters for the same sample. ...

AI Technical Summary

Problems solved by technology

[0005] In the past, when testing the basic strength and deformation characteristics of the soil, only a single index of the soil can be tested each time, such as the compressive modulus of the soil, the undrained strength of the clay, the side friction resistance, the shear strength or the shear modulus. etc., there is no test equipment for comprehensive measurement of multiple parameters for the same sample

[0006] In the past, in the indoor static penetrating test of soil, usually only the cone tip resistance was measured, without considering the influence of side friction resistance, and the obtained test data was not accurate.

At the same time, due to the lack of real-time monitoring of pore water pressure during the penetration process, it is impossible to make reasonable corrections to the resistance of the cone tip, and the resistance of the cone tip cannot reasonably reflect the mechanical properties of the soil, and it is impossible to evaluate the seepage and consolidation characteristics of the soil.

The reliability of soil stratification and soil classification cannot be guaranteed

[0007] In the past, the cross-plate shear test was used to test the undrained shear strength of the field soil. The cross-plate shear tester developed for the indoor test is often not designed according to the change of the shear strength index of the expansive soil during the freeze-thaw cycle. , so the shear strength of the same soil sample under different freeze-thaw cycles cannot be provided

[0008] In the past, synchronous sampling was not set during the indoor test, which made the analysis of the test results lack of basis, and the current basic physical properties of the soil could not be monitored and fed back.

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