Rock-soil body temperature-control dynamic characteristic test system and test method

Abstract

The invention discloses a rock-soil body temperature-control dynamic characteristic test system and method, is characterized in that the system includes a dynamic triaxial pressure chamber and a temperature control device; the dynamic triaxial pressure chamber comprises a pressure chamber cylinder body, a piston rod and an upper dowel bar; a sample is arranged between the lower end of the upper dowel bar and the upper end of the piston rod; the dynamic triaxial pressure chamber also includes a pressure sensor, an axial displacement sensor, a deformation sensor, a confining pressure sensor, a lateral displacement sensor and a pore pressure sensor; the temperature control device includes a temperature sensor, a temperature controller and an arc plate type heater symmetrically coating the outer wall of the pressure chamber cylinder body. The temperature-control dynamic characteristic test method mainly includes installing the sample, setting the temperature control device, carrying out drainage consolidation of the sample, applying dynamic / static stress, and completing a temperature-control dynamic / static triaxial test, to determine the cumulative plastic strain, dynamic damping ratio, dynamic elastic modulus and other indexes of a rock-soil body under different temperatures. The system and the method have the advantages of uniform heating temperature, short heating time and low cost, and can accurately control the temperature in the pressure chamber.

Description

technical field [0001] The invention belongs to the technical field of soil engineering tests, and in particular relates to a test system and a test method for temperature-controlled dynamic characteristics of rock and soil. Background technique [0002] Earthquake force, wave force, explosive force, piling vibration, dynamic foundation force and traffic load in the construction process of railways, highways, ports and urban rail transit all belong to the category of dynamic loads, which affect the strength and deformation of foundation soil. It is very necessary to carry out the dynamic characteristic test of soil to obtain various dynamic characteristic parameters. The purpose of the soil dynamic characteristics test includes two aspects: one is to determine the dynamic strength of the soil, which is used to analyze the stability of the foundation and structures under large deformation conditions, especially the vibration liquefaction of sandy soil; the other is to determi...

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Problems solved by technology

Although this type of device saves the development process of the instrument, the cost of establishing a temperature-controlled laboratory is relatively high, the test environment is poor, and the requirements for high temperature resistance of each component of the instrument are high.

[0005] (2) The heating mode in the pressure chamber uses heating coils, heating tubes, heating rods, and heating plates to heat the fluid. This heating method directly heats the fluid, which can better meet the test temperature requirements, but it is not easy for the pressure chamber under high confining pressure. The liquid is heated evenly, so that the temperature of the sample is not uniform

[0006] (3) In the pressure outdoor heating mode, the coil is wound outside the pressure chamber, and the fluid in the pressure chamber is heated by the heating coil. Since the temperature of the liquid in the pressure chamber needs to be increased through heat transfer through the outer cover, it will take time for the sample to reach the test temperature requirement. longer

[0007] Because the engineering properties of rock and soil will change under the action of different temperatures, heating can reduce the viscosity of pore water in the sample, increase the permeability coefficient, and induce thermal expansion of pore water and soil particles to make the soil sample The trend of volume increase, under the same vibration times, the cumulative plastic strain, dynamic damping ratio, dynamic elastic modulus, etc. of the rock and soil mass will all change. Therefore, a test system and method for the dynamic characteristics of rock and soil temperature control based on the combined internal and external heating mode are proposed.

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