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The study of rock burst tendency of rock masses with different sizes plays a key role in the prevention of rock burst. Through theoretical analysis, it is proposed that uniaxial compressive strength and deformation modulus ratio are the key mechanical parameters affecting rock burst occurrence. In order to find out the size effect of uniaxial compressive strength and deformation modulus ratio, theoretical analysis and uniaxial compression experiment are carried out on rock samples with different heights, different cross-sectional areas and different volumes. The results show that the smaller the uniaxial compressive strength is, the larger the deformation modulus ratio is, and the more likely rock burst are to occur. On the contrary, rock burst is still not easy to generate. The uniaxial compressive strength of rock samples with different heights, different cross-sectional areas and different volumes increases with the increase of rock sample size. The deformation modulus ratio of rock samples with different heights and different volumes shows an upward trend on the whole, while that of rock samples with different cross-sectional areas shows a downward trend on the whole. The fracture forms of rock are analyzed using the energy conversion law in the process of deformation and failure for three kinds of rock with different shapes and sizes. [ABSTRACT FROM AUTHOR]

Landslide-tsunami formed by landslide impacting into water severely threatens the life and property safety of residents along coastal areas. The slide impact angle of landslide (α) is an essential parameter in landslide-tsunami prediction. Many studies have discussed the response laws of formation features of landslide-tsunami to the comprehensive effect of α and several other factors. However, the influencing laws of α on landslide-tsunami features vary and are even contradictory among different studies. To determine the independent effects of α on wave generation, this study used a numerical simulation correction on the correction utilized smoothed particle hydrodynamics (SPH) method, which verified the efficacy of SPH method in simulating landslide-tsunamis. Next, three groups of landslide-tsunami numerical simulation tests under different α (10°, 20°, and 30°) were implemented to analyze the influencing laws of α on water motion features, water occupation by the landslide, and energy conversion law thoroughly. Results demonstrate that the SPH method could simulate the generation and propagation of landslide-tsunami well, achieving a relatively high simulation accuracy. The landslide and water movements in the three groups of numerical simulations are similar. As α increases from 10° to 30° successively, the rate of water occupation by the landslide decreases gradually, but the volume of water occupied by the landslide increases. The maximum occupational volume reaches 7.91 times as that of landslide. After the landslide enters the water, the energy attenuation rate increases with the increment of α, and it reaches the lowest at α = 10°. Generally, with α increasing, the amplitude of the first wave decreases, while the amplitude of the second wave increases. The proposed conclusions provide some references to constructing the landslide-tsunami prediction model. [ABSTRACT FROM AUTHOR]