After the erection of the Three Gorges Dam, the water level of Yangtze River will reach 175 m, and the average wave crest will be up to 1 m. Therefore the wave action cannot be neglected for the slope stability. Through simulation tests, the wave-induced dynamic response of the slope is analyzed. The soil body is taken as linear elastic body when it has a small deformation under the small wave action. Based on tests, the excess pore pressure and slope displacement under the loading in different wave period are analyzed. The ratio of dynamic strength and static strength to the breaking process of the slope is discussed. It is demonstrated that smaller wave period gives rise to a larger strain of the slope under the same stress. At different depth of water, different weakness effect on the stability of the soil slope is observed and the slope has an adaptability to the wave action to some extent.
The characteristics of acoustic emission (AE) signals given off in the course of the failure of a concrete structure is explored based on the laboratory experiments with concrete specimens. It is observed that the failure of a concrete structure experiences three stages divided by two inflexion points on the AE event curve, which are sequentially no damage, damage initiation and propagation, and major failure stages. In the first stage, existing micro cracks and defects are compacted by loading, but no damage propagated, hence few AE signals are detected, and it appears that there exists a nearly linear relationship between the relative stress and relative strain. In the second stage, the AE event frequency increases, implying that micro cracks begin to emerge inside the concrete structure, which is consistent with the damage mechanics. When the load is over 80 % of that breaks the structure, i.e. the maximum load, there is a vertical jump on the AE event count curve, which suggests that the failure propagation speeds up. After the second inflexion point, the AE event density increases faster than before, and there is another jump just before breaking, which indicates a quick propagation stage. These findings are valuable for evaluating the damage situations, and for studying and monitoring the dynamic process of the failure behaviors of a concrete structure.
Based on the fundamental principle of rock mechanics, the stresses of single joint rock mass under three-dimensional compression were analyzed. The effect of the in-termediate principle stress on the strength of single joint rock mass were discussed in par-ticular. It is found that the strength of single joint rock are affected by the intermediate principal stress, which may be the main factor in some conditions.
