Search

Using statistic and bibliometric methods to characterize scientific cooperation between China (excluding Hong Kong, Macao, and Taiwan) and South Korea through their bilateral co-authored papers covered by the Science Citation Index CD-ROM, 1991-2010, in our paper we exploit the feature of their cooperation in four levels: time sequence, academic community, key fields, and institution distribution. From the time sequence we know that collaboration between China and Korea starts in 1991, reaching the first peak during 2004-2007. As for the academic community, the number of Chinese corresponding authors (2414) is slightly lower than that of Korea (2700). Regarding the 27 high yield authors, there are only 4 coming from China. Korea has a higher active level than Chinese authors. China and Korea tend to cooperate with each other on strong disciplines such as physics, chemistry, material science, engineering, mathematics, pharmaceutical, computer science and biology. Furthermore, they also attach great importance to basic research and high-tech cooperation. Besides, Chinese Academy of Sciences ranks at the top 1 among the distribution of institutions. As a majority of the collaborative institutions are universities, the participation of non-university institutions is relatively low. There are 7 Korean universities among the top ten institutions, while Yanbian University and Tsinghua University in China rank respectively as third and fourth. Seoul National University, accompanied by Korea University and Yonsei University as the three top Korean universities, is also among the top among the cooperating institutions.

Under the Castor earthquake, there is a risk of liquefaction instability of saturated tailings, and the evolution of dynamic pore pressure can indirectly reflect its instability process. Before applying dynamic loads, the static stress state of soil is one of the main factors affecting the development of soil dynamic strength and dynamic pore pressure, and there are significant differences in soil dynamic strength under different consolidation ratios. This paper conducted dynamic triaxial tests on saturated tailings silt with different consolidation ratios, and analyzed the dynamic strength variation and liquefaction mechanism of the samples using the discrete element method (PFC3D). The results showed that 1) as the Kc′ gradually increased, and there was a critical consolidation ratio Kc′ during the development of the dynamic strength of the sample. The specific value of Kc′ was related to the properties and stress state of saturated sand. The Kc′ in this research was about 1.9. When Kc < 1.9, dynamic strength was increased with the increase in Kc; when Kc > 1.9, dynamic strength was decreased with the Kc. 2) Under the impact of cyclic load, when samples were normally consolidated (Kc =1), the pore water pressure would tend to be equal to the confining pressure to cause soil liquefaction. In the case of eccentric consolidation (Kc > 1), the pore water pressure would be less than the confining pressure, thus, the soil liquefaction would not be induced, and the pore pressure value would decrease with the increase of consolidation ratio. This paper provides engineering guidance value for the study of dynamic strength and liquefaction mechanism of tailings sand and silt in Castor earthquake prone areas under different consolidation ratios.