Unsaturated soil multifunctional triaxial apparatus and sample preparation device thereof

Abstract

The invention discloses an unsaturated soil multifunctional triaxial apparatus and a sample preparation device thereof. The triaxial apparatus comprises a rack, a pressure chamber, a precision volumechange measuring device, an axial load piston, an axial load sensor, a displacement sensor, an axial load and axial deformation rate control / data acquisition and processing system, a water-gas-circuitcontrol cabinet, a water supply device and a microcomputer. Suction can be conveniently applied or controlled, strain rate can be controlled to be constant, and deviator stress can also be controlledto be constant. A sample can be immersed in a certain stress state, after swelling / collapsibility / soaking deformation is stable, the suction is applied to perform drainage and dehumidification, the influence of drying and watering cycle under triaxial stress conditions on mechanical properties of soil is researched, pore air pressure is measured by a micro-sensor, triaxial shear test without drainage or exhaust can be performed, and the pore air pressure is accurately measured. Volume change measuring precision is high, errors are small, sample preparation is simple, convenient and rapid, thedry density of the sample can be accurately controlled, and sample preparation efficiency and the technical level of sample preparation are improved.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering testing equipment, and in particular relates to a multifunctional triaxial instrument for unsaturated soil and a sample preparation device thereof. Background technique [0002] Most of the soil encountered in the project is in an unsaturated state, such as earth dams, embankments, slopes, etc. Suction is a stress variable of unsaturated soil, which has a great influence on the deformation, strength and other mechanical properties of unsaturated soil. For example, expansive soil and collapsible loess, which are widely distributed in my country, are typical unsaturated soils. They have large strength and modulus, high bearing capacity and small deformation in dry state (high suction); When it is larger (low suction), the strength and modulus are greatly reduced, the bearing capacity is low, and the deformation is large; if it is soaked in water, the suction will decrease, and expan...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a kind of unsaturated soil multifunctional triaxial instrument and sample preparation device thereof, aim to solve the following two problems: ① traditional triaxial instrument can not consider the effect of suction, only applicable to saturated soil; ② traditional method Using compaction equipment to prepare remolded soil samples for triaxial tests is relatively rough and inefficient, and the dry density of the samples cannot be accurately controlled

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