XU R C, YAN Z, ZHOU W P, et al. Experimental study on the effect of water saturation on the tensile strength and acoustic emission characteristics of white sandstone [J]. Journal of Henan Polytechnic University (Natural Science) , 2025, 44(4): 160-169.

doi: 10.16186/j.cnki.1673-9787.2023120016

Received: 2023/12/07

Revised: 2024/04/30

Published: 2025/06/19

Experimental study on the effect of water saturation on the tensile strength and acoustic emission characteristics of white sandstone

Xu Rongchao1, Yan Zhen1, Zhou Wenpeng2, Hu Yubo1, Wang Yibo1, Gao Liang1

1.College of Geosciences and Engineering， North China University of Water Resources and Electric Power， Zhengzhou  450046， Henan， China；2.Sinohydro Bureau 11 Co.， Ltd.， Zhengzhou  450001， Henan， China

Abstract: Objectives To investigate the mechanical degradation of white sandstone under water saturation by analyzing the macroscopic effect of saturation on tensile strength， acoustic emission （AE） characteristics， and fracture surface morphology. Methods Brazilian splitting tests and real-time AE monitoring were conducted on white sandstone specimens in both water-saturated and natural （dry） states to assess the effect of water saturation. Results The experimental results indicate that： （1） Saturation leads to the dissolution of mineral particles within the white sandstone， reducing the cohesion between particles， causing mechanical damage and an 11.3% decrease in tensile strength； （2） The deformation and strength reduction caused by saturation result in a significant decrease in the unit area splitting energy during loading； （3） After saturation， the acoustic emission count and cumulative energy weaken during early activity， with their  peak values occurring later than the peak load； （4） Acoustic emission RA-AF analysis shows that the proportion of tensile fractures decreases after saturation， while shear fractures increase. In both saturated and natural states， shear fractures increase sharply near peak load； （5） The acoustic emission b-value decreases after saturation，  indicating a reduction in small-scale fractures and an increase in large-scale fractures during splitting. A sharp drop in real-time b-value during loading can serve as a precursor to specimen failure； （6） Saturation causes a decrease in roughness indicators of the splitting joint surface， including root mean square slope， roughness profile index， actual joint surface area， and roughness coefficient. Conclusions Water saturation significantly reduces the tensile strength of white sandstone， increases the proportion of large-scale fractures， and results in a smoother fracture surface. 

Key words: water saturation; sandstone; tensile strength; acoustic emission; joint surface morphology