Clayey soil strain control type uniaxial extension meter

Abstract

The invention discloses a clayey soil strain control type uniaxial extension meter. The uniaxial extension meter disclosed by the invention comprises a triaxial instrument, an extension system extending a specimen and a strain measuring system, wherein the extension system comprises a base capable of being lifted, a specimen cap and a connecting rod; the two ends of the specimen are respectively linked with the base and the specimen cap; the measuring system comprises a sensor and a digital display instrument; and the sensor measures a tensile force which is borne by the specimen and displaysthe tensile force through the digital display instrument. The uniaxial extension meter disclosed by the invention does not need to improve a conventional triaxial instrument, can carry out an extension test on specimens with different lengths, can overcome the defects of overlarge measuring force rigidity and over-small deformation of the original triaxial instrument, can improve extension stresstesting accuracy and stability and has the advantages of simplicity and convenience in operation and low cost; the extension test is carried out by adopting the extension meter disclosed by the invention; the stress distribution in the specimens is uniform; specimen damage occurs in the middle part of the specimens; and the extension stress and the extension deformation can be effectively measured, thereby searching the stress-strain relation of soil extension.

Description

technical field [0001] The invention relates to a stress measuring device in civil engineering and geological engineering, in particular to a uniaxial extensometer which can improve the precision and stability of stress measurement. Background technique [0002] Tensile strength and its stress-strain relationship under tension are one of the basic mechanical properties of soil. Because the tensile strength of soil is much lower than the compressive strength and shear strength, it is often ignored in many practical problems, so there are few studies on the tensile strength of soil and its stress-strain relationship under tensile conditions. So far, there is no standard for the test instrument of soil tensile strength. [0003] However, many problems in actual engineering are related to the tensile strength of the soil, such as the tensile cracks at the top of the slope when the soil slope slides, the hydraulic splitting of the core wall of the earth-rock dam, and the ground ...

AI Technical Summary

Problems solved by technology

The difficulty of the direct tensile test mainly lies in the application of the axial tensile force at the end of the sample and the measurement of the tensile stress during the test. These problems have not been well resolved in the existing tests, resulting in stress concentration at both ends of the sample. , so that the tensile cracking failure occurs at the end of the sample instead of in the middle of the sample, the stress measurement accuracy and stability are poor, and it is difficult to obtain the stress-strain relationship curve of soil tension

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