| Ultrasonic testing technique in rock mass medium is a new technique which has been developed during near forty years. It realized physical and mechanics characters, structure and stress state of rock mass by testing the change of acoustics parameters of sound wave signal after penetrating rock mass, which got recognition in domestic and overseas geotechnical engineering fields. Rock would be damaged inside when it endures uniaxial compression, According to the ultrasonic characteristic parameters, we can judge the statement of the rock sample which is stayed while it is in compression process, thus providing more reference significance for studying about the elastic limit and stress-strain features of rock.In this thesis, we study the propagation characteristics of ultrasonic waves which go through rock containing different amounts of water by ultrasonic testing which during the uniaxial compression. Through the analysis of rock ultrasonic parameters and stress-strain curve, we study the effect of the degree of saturation to acoustic parameter, strength of rock, elastic properties of rocks, etc. In this thesis, results are as follows:(1) Rock acoustic velocity first increases and then decreases with pressure increasing. Small pores which are inside the rock close down easily when the rock under low pressure, while a large number of pores closed, acoustic velocity will be significantly increased. With the pressure increasing, closed pores opening again, the new generation and extension of micro-cracks make velocity decrease.(2) The degree of saturation of rock makes effects on physical and mechanical properties of rock, with the increasing of water content of rock, the rock compressive strength decreases nonlinearly. During the rock filling process, the adsorbed water which is on the surface of mineral particles and pore wall has a great influence on elastic modulus and strength, in other words, water-rock effect causes particles softening, links between the particles and other degrading weakened which effects significantly larger.(3) Influence of Moisture Content on rock acoustic parameters is obvious. In the process of water naturally saturated rock, the acoustic wave velocity decreases with the increase of water saturation of rock, from the dry state to the full water level 70%, the wave velocity is slowly decreased and a linear trend is presented, when the water saturation is 70% to 100%, the speed of the wave velocity decreases obviously; the acoustic amplitude appears to decrease first and then increase with the increase of water saturation of rock, which can be fitted by quadratic function, from the dry state to the full water degree 50%, the wave amplitude decreased obviously, when the saturation degree is about 50% to 80%, the amplitude reaches the lowest value, from the saturation of 80% to 100%, there was a significant increase in the volatility. |
