Experimental Study on the Influence of Permeation Deformation of Limestone with Different Moisture Contents in Deep-Water Environments

This study deeply explores the permeation deformation mechanism of limestone cores in deep-water environments. Through a customized test device, the mechanical responses of deep-water rocks under different moisture content conditions are simulated. The device is composed of a pressurization system, a pressure vessel, and a data acquisition system, which can accurately apply high water pressure and monitor the stress and strain changes in the core in real time. The cores used in the experiment were cut to standardized sizes and subjected to strict saturation and drying treatments to ensure the consistency of test conditions and the accuracy of data. The mechanical behaviors of cores under four working conditions of dryness, 50% moisture content, and 100% moisture content are analyzed. Through the cyclic process of pressurization and depressurization, the changes in the strain characteristics of the cores are observed. The research results show that when pressure is applied for the first time, low moisture content cores will absorb water and expand, and the strain will increase and then tend to be stable as the pressure increases. There is no such process for cores with 100% moisture content. Water pressure is positively correlated with the elastic modulus of rocks, negatively correlated with the strain rate during pressurization, and positively correlated during depressurization. Moreover, an increase in moisture content reduces the average strain mutation, reduces the average strain rate amplitude, and increases the elastic modulus. This study provides important theoretical support for the design and construction of deep-water rock engineering and provides a reference for further research in related fields.