• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.828-835
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• 2019

An artificial rainfall system is used widely as a research tool for generating model experiment data. Artificial rainfall devices have been used in many studies, but studies of the rainfall distribution are not considered as important issues. To simulate various rainfall characteristics, it should be possible to simulate from low to high intensity, and the homogeneity of the rainfall distribution should be ensured. In this study, the maximum rainfall intensity was set to 130mm/hr and controlled by 10mm/hr. In addition, the aim was to secure a uniform coefficient value of 80% or more. To this end, rainfall tests were performed according to the nozzle type, diameter, position, and pump pressure. The rainfall test showed that the circular nozzle was suitable, and the nozzle size was 1.9mm and 1.4mm. The optimal pump pressure was found to be 3~6kg/㎠. The rainfall intensity tended to increase linearly with increasing pump pressure. Based on the rainfall test results, a rainfall control manual was produced with variables, such as pump pressure, nozzle type, and number of nozzles. As a result of rainfall verification, rainfall intensity showed a 3.1% error with a uniformity coefficient of 86%.

• Journal of the Korean GEO-environmental Society
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• v.24 no.8
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• pp.5-11
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• 2023

Due to frequent occurrences of concentrated heavy rainfall caused by abnormal climate conditions in recent years, collapses of steep slopes have been occurring frequently due to surface erosion and increased pore water pressure. Various methods are being applied to prevent slope collapses, such as increasing the resistance to movement and reducing pore water pressure. Research on these methods has been consistently conducted as they provide an efficient response to slope collapses by satisfying both the conditions of resistance to movement and pore water pressure simultaneously. Therefore, in this study, we propose an upward slope reinforcement method by burying drainage materials with an upward slope inclination, instead of the conventional horizontal application. This approach aims to satisfy both slope reinforcement and drainage functions effectively, offering a comprehensive solution for slope stabilization. Furthermore, to determine the optimal burial angle that exhibits the most effective reinforcement and drainage effects of the proposed method, we investigated the reinforcement and drainage effects under conditions where the horizontal drainage materials were set at angles ranging from 0° to 60° in increments of 10° on a representative cross-section. Additionally, indoor model experiments were conducted under the conditions of 40°, which showed the most outstanding drainage effect, and 20°, which exhibited the highest safety factor, to validate the numerical analysis results. The results showed that the burial angle of 40° exhibits a relatively higher drainage effect as with the numerical analysis results, while the angle of 20° results in inadequate drainage and observed slope collapse.