Novel apparatus for visualizing hydraulic fracturing in soils

Abstract

This paper presents a new apparatus designed specifically for visualizing hydraulic fracturing in soils. The apparatus comprises four main units: an injection cell, a visualization unit, a pressure/volume control unit, and a data acquisition unit. The injection cell is characterized by a transparent, high-transmittance polymethyl methacrylate top cover that enables direct visual observation. The visualization unit includes a visual studio and a high-resolution camera that captures macro-fracturing dynamics. The pressure/volume control unit enables specific test requirements to be satisfied during injection tests. The data acquisition unit records injection pressure and water volume data over time. To validate the performance of the novel apparatus, we conducted a systematic injection test on Gaomiaozi bentonite with a dry density of 1.3 g/cm3 and a water content of 9.39%. The results indicate that the apparatus accurately captures macro-fracturing dynamics and records injection pressure and water volume data in real-time.