The hydromechanical coupling behavior of rocks is widely present in the fields of rock mechanics and engineering studies. Analyzing and summarizing the relevant literature, the current status of experimental and coupling theory research on hydromechanical coupling is systematically described, the commonly used numerical simulation methods and their applications are briefly introduced, and the hydromechanical coupling problems in mining engineering, water conservancy, and hydropower engineering, slope engineering, tunneling engineering, and other fields are analyzed. Regarding the current status of studies on the hydromechanical coupling behavior of rocks, the test research aspect needs to further enhance the test studies on the triaxial shear permeability of rock material, and adopt a combination of macroscopic, fine, and microscopic methods to study the hydraulic coupling problems of rock materials from different scales. To couple theory, the traditional concepts are broken through, and new coupling theories and mathematical models are used to explain and solve the relevant practical problems. Meanwhile, the application of interdisciplinary approaches to solving coupling problems in the future is emphasized. In terms of numerical simulation and engineering applications, new large data algorithms are developed to improve the efficiency of simulation calculations. In addition, consideration should be given to the numerical simulation of coupling effects, the coupled rheological effects, and the coupled dynamic properties of rock masses under high-ground stress and high water pressure.

The seepage characteristics of rocks under conditions of multi-field activity have always been important in the field of rock mechanics. This study used the MTS815 multi-functional electro-hydraulic servo rock testing machine to conduct seepage tests on long-flame coal specimens under different confining pressures, water pressures, and temperatures. This paper presents and discusses the seepage characteristics of coal specimens under the action of thermal hydraulic mechanical multi-field combinations. Considering parameters such as volumetric strain, temperature, thermal expansion coefficient, and initial porosity, the relationships of each parameter with porosity were obtained. The test results revealed that the volumetric strain of coal specimens increased gradually with the increase of temperature. The dynamic viscosity of water decreased with the increase of temperature, which accelerated the movement and circulation of water molecules. The increase in temperature caused the volume of the coal specimen to expand, the pores in the coal specimen squeezed against each other, the pore volume decreased, and the size of the seepage channel slowly decreased, which inhibited the seepage process. Furthermore, permeability gradually decreased with the increase of temperature. This inhibited the occurrence of seepage, and the higher the confining pressure, the lower was the permeability. The porosity of coal specimens decreased with the increase in temperature, which had an inhibitory effect on the seepage behavior. The results of this study provide experimental and theoretical support for the safe mining of coal and rock in underground mines.

The air-lifting pump has the advantages of low cost, strong reliability, simple structure and convenient maintenance, especially in the fields of deep-sea mining, oilfield mining and mineral mining under complex geological conditions. The construction technology and air intake mode not only play a decisive role in the performance of the air-lifting pump, but also greatly hinder the engineering application of the air-lifting pump. Here, the air-lifting pump is taken as the research object, and the river sand is used as the experimental transport medium. The particle concentration-efficiency model is established based on the mechanical energy conservation theorem. The working performance characteristic parameters of the air-lifting pump under different construction technologies are obtained by a three-axis motion control system. On this basis, the working performance characteristic parameters of the air-lifting pump under different intake modes are obtained by changing the intake mode. The results show that the particle concentration-efficiency model can well describe the efficiency of lifting solid particles by the air-lifting pump. When the sand depth is less than 200 mm, the concentration and efficiency of solid particles transported by the air-lifting pump in the horizontal movement construction are significantly better than those in the fixed position construction. In the same construction technology, the solid particle concentration of the air-lifting pump in uniform intake mode is better than that in non-uniform intake mode, while the transportation efficiency of the air-lifting pump in non-uniform intake mode is better than that in uniform intake mode. The research results of this paper can provide an important theoretical reference value for the air-lifting pump in practical engineering applications.