Effect of Dry-Wet Cycling on the Mechanical Properties of Rocks: A Laboratory-Scale Experimental Study

Xiaojie Yang,Chun Zhu,Manchao He,Dinggui Hou,Jiamin Wang

doi:10.3390/pr6100199

Abstract

Taking Nanfen open-pit iron mine in Liaoning Province as the engineering background, this study analyzes the effect of water-rock circulation on the mechanical properties of rock through a combination of macro-mechanical experiments and microstructure tests in the laboratory. Uniaxial compression experiments and acoustic wave tests are used to determine the degradation law of the mechanical properties of chlorite under the periodic action of water. The experimental results show that dry-wet cycles have a continuous and gradual effect on the rock sampled: Its uniaxial compressive strength, elastic modulus, and acoustic velocity all decrease gradually with an increase in the number of cycles. After 15 wet-dry cycles, the uniaxial compressive strength and elastic modulus of the rock decreased by 34.21% and 44.63%, respectively. Electron microscope scans of the rock indicate that the particle size, characteristics, and pore distribution at the rock surface had changed significantly after water-rock interaction. Finally, a drainage system and sliding force monitoring devices have been arranged at the mine site that can effectively reduce the impact of water-rock interaction on the stability of the mine. This combination of macro-experiments and micro-analysis allowed the weakening effect of dry-wet cycles on slope rock to be studied quantitatively, providing a theoretical reference for stability evaluation in geotechnical engineering.

Highlights

Geotechnical engineering problems have been on the increase in recent years in concert with the continuous expansion of geotechnical projects such as water conservancy projects, deep coal mines, and slope projects [1,2]
Based on the engineering background of Nanfen open-pit iron mine in Liaoning province, this study investigated the mechanical properties of rocks subjected to water-rock circulation through macroscopic mechanical experiments, microstructure tests, and theoretical analysis
Periodic water circulation due to rainfall, evaporation and the fluctuation of groundwater level was simulated in the laboratory, and valuable data were obtained regarding its effect on the mechanical property parameters of these Nanfen chlorite rocks

Summary

Introduction

Geotechnical engineering problems have been on the increase in recent years in concert with the continuous expansion of geotechnical projects such as water conservancy projects, deep coal mines, and slope projects [1,2]. [3,4] it is essential to evaluate and ensure rock mass stability in order to solve geotechnical engineering problems effectively. From the perspective of geotechnical engineering, the interaction between water and rock is essentially a continuous physical, chemical, and mechanical process. This process changes the physical and mechanical parameters of the rock, causing a loss of stability in geotechnical engineering contexts [7]

Methods

Results

Conclusion