Experimental Investigation of Mechanical Behavior of Sandstone with Different Moisture Contents Using the Acoustic Emission Technique

Abstract EN

The moisture content is a critical factor tightly related to rock deformation and its failure process since it leads to a significant change in the physicomechanical properties of rock during the underground engineering construction.

As a result, engineering construction accidents take place frequently.

To figure out the influence of the moisture content on the physicomechanical properties of water-bearing rock and then effectively avoid engineering accidents, multiple tests including the uniaxial compression test, Brazilian splitting test, and the acoustic emission (AE) test were carried out in this study.

The experimental results showed that the water absorption rate of the sandstone gradually stabilizes after 5 h, and its uniaxial compressive strength, tensile strength, and elastic modulus all decline with the increase of the moisture content.

Compared to the dry state of the sample, the reduction amplitudes of the elastic modulus, compressive strength, and tensile strength of water-saturated rock samples can reach up to 27.3%, 35.2%, and 38.1%, respectively.

It indicates that the tensile strength is more sensitive to the softening effect of the moisture.

Through the AE test, it can be found that the internal state of water-saturated rock samples is greatly changed; the compressive strength of rock samples drops, so the rock can be damaged after absorbing less energy.

Thus, moisture shows a certain softening effect on rock.

The research results are expected to provide a basis for underground engineering construction and rock fracture and failure.