Large triaxial shear testing instrument for rockfill material degradation

Abstract

A large triaxial shear testing instrument for rockfill material degradation is characterized by comprising a test mainframe, a confining pressure and pore pressure servo loading system, a temperature control system, a closed loop measurement and control system and a computer control and data acquisition system (15). The large triaxial shear testing instrument for rockfill material degradation adopts a multichannel closed loop controller to realize two-way independent high-precision control for axial loading and lateral loading of a servo motor and a reducer ball screw, and a mechanical property test for a rockfill material under a complex stress path can be carried out; the large triaxial shear testing instrument for rockfill material degradation adopts a cold and hot control device provided with a temperature control pump, an acid-base circulating device and an anti-corrosion pipeline, so that physical weathering and chemical weathering tests can be performed simultaneously; and the large triaxial shear testing instrument for rockfill material degradation adopts a differential displacement sensor and a diameter deformation measurement sensor, and accordingly, accurate measurement of a dynamic size change process in a dry and wet change process of a rockfill material test piece is realized.

Description

technical field [0001] The invention belongs to the technical field of test devices, and relates to equipment for testing the deterioration performance of rockfill materials for high earth-rock dams, in particular to a large-scale triaxial shear tester for the deterioration of rockfill materials. The invention is mainly used to measure the mechanical properties of rockfill materials in the process of physical weathering (dry and wet and cold and heat) and chemical weathering (acidification), and also has the ability to carry out complex stress paths and rheological and humidification of high earth-rockfill dam rockfill materials. Experimental research function. Background technique [0002] At present, rockfill materials are the main materials for building high earth-rockfill dams. In order to save engineering investment and protect the ecological environment, some excavated rockfill materials that are prone to weathering lithology near the dam site have been widely used in ...

AI Technical Summary

Problems solved by technology

With the improvement of construction level and rolling process, the maximum particle size of rockfill materials has reached 120cm, while the maximum particle size allowed by the above-mentioned test equipment is only 3cm, and the scale effect is too large;

[0005] (2) Only the K0 consolidation test can be carried out, and the experimental research on the complex stress path cannot be carried out, and it cannot be used to determine the calculation parameters of the constitutive model of the commonly used rockfill materials at present;

[0006] (3) Only physical weathering test can be carried out, chemical weathering test cannot be carried out

With the intensification of weathering caused by acid rain caused by global environmental pollution, the impact of environmental changes on engineering will become more and more significant. Therefore, it is necessary to study the strength and deformation characteristics of rockfill materials after chemical weathering, but existing instruments do not have this function ;

[0007] (4) The existing large-scale triaxial test equipment can only test the volume deformation of saturated samples, but cannot measure the volume deformation of dry samples

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