Micro-loess unsaturated suction control loading device and method for separable pressure chamber

Abstract

The invention discloses a miniature loess unsaturated suction control loading device and method for a detachable pressure chamber. Indoors, the support assembly on one side of the detachable pressure chamber is provided with a displacement sensor for measuring the vertical displacement of the soil sample, and the power device is arranged above the detachable pressure chamber to provide a driving force for rotation of the detachable pressure chamber . The invention has the advantages of simple structure, convenient operation, miniaturized overall structure, and the ability to separate a sample in an unsaturated state from a loading device for scanning by high-precision CT.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering tests, and in particular relates to a miniature loess unsaturated suction control loading device and method for a separable pressure chamber. Background technique [0002] For silty clay represented by loess, its suction and permeability characteristics under unsaturated conditions are the core of seepage problems and strength analysis in the field of geotechnical engineering. The unsaturated permeability coefficient and suction state of the soil are closely related to the soil structure. The porosity of the soil, the combination of particles, and the overhead structure composed of the aggregates formed by the clay particles all have a fundamental impact on the unsaturated permeability characteristics and suction of the soil. Therefore, quantifying the structure of soil is the basis for quantitatively analyzing the unsaturated permeability and mechanical behavior of soil. [000...

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Problems solved by technology

However, the existing defects of using high-precision CT to observe and study the microstructure of silty clay are: the X-ray power used by micro-CT to ensure the imaging accuracy is low, and the conventional soil samples are large in size and cannot be directly imaged; in addition, when the soil In the observation state, the soil needs to be removed from the loading equipment before it can be scanned in the micro-CT, so the obtained soil structure is not in the loaded state but in the unloaded state; again, the current silty clay such as loess None of the CT scanning tests performed applied a specific suction state to the soil, but for silty clay such as loess, the structure under specific suction conditions is the core issue of the physical and mechanical properties of this type of soil

On the market, the volume of unsaturated loading equipment using this technology cannot meet the requirements of microscopic CT scanning. The reasons are: the large sample size and the volume of the pressure chamber make it impossible for low-energy X-rays to penetrate its structure for imaging; The technical requirements for microscopic soil samples to be scanned by microscopic CT under the condition of imposing a certain unsaturated state and maintaining this state

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