The objective of this study was to establish a method to calibrate a large-scale laboratory rainfall simulator through developing and implementing an automated rainfall collection system to assess the reliability and accuracy of a rainfall simulator. The automated rainfall collection system was designed to overcome the limitations caused by the traditional manual measurement for obtaining the rainfall intensity and the spatial rainfall distribution in a large experimental area. The developed automated rainfall collection system was implemented to calibrate a large-scale laboratory rainfall simulator. The adequacy of average rainfall intensities automatically collected from the miniature tipping bucket rain gauges was assessed by comparison with those based on the volumetric method using the flowmeter. The functional relationships between the system variables of the rainfall simulator and the simulated intensity and uniformity distribution of rainfall (i.e., operation models) were derived based on a multiple regression approach incorporating correlation analysis on linear and logarithm scales, with consideration of a significance level. The operation models exhibited high accuracy with respect to both the rainfall intensity and the uniformity coefficients.

This paper studied the current and future of an early warning system (EWS) for slope failure. Details of the developed Korea EWS were reviewed and compared; its future was then predicted by the studied results and global trends. Slope failure mechanisms for the Korea EWS were developed based on rainfall, rainfall with ground/geology characteristics, and measurement results using measuring equipment. Among the early warning systems, 5 types of models (Half-period, Soil Water Index, Continuous rainfall, Rainfall Triggering Index, and measuring equipment) were analyzed. Afterwards, 4 models (excluding measuring equipment) were compared. Finally, the future of the Korea EWS was predicted within the Korea Smart City System.

Biomass has become one of major sources of renewable energy, but, after combution, the ashes of biomass are not well recycled. The compressibility and thermal characteristics of biomass ashes were experimentally analyzed and compared to silica sand, in attempt to utilize the biomass ashes as sustainable construction material. The mean particle sizes of wood and sugarcane bagasse ashes were 0.15 mm and 0.04 mm, respectively; the particles were angular and had non-uniform array. The compressibility of biomass ashes were much larger than those of sands with the same initial loading; the thermal conductivity lower. In addition, the more saturated, the higher thermal conductivity. The compressibility and thermal characteristics of biomass ashes, reported in this paper, are for uniform materials that contain relative high void contents; the mixture of soil and biomass ashes, which has denser composition, needs to be inspected further.

This paper describes the Measurement Management Criteria (MMC) of a soil slope failure based on displacement using literature reviews, small-scale experiments, large-scale experiments, and field data. Two types of measurement management criteria were developed, i.e., short-term criteria for slopes under construction or requiring urgent measurements, and long-term criteria for slopes under continuous management. First, the measurement criteria for the short term were determined based on small- and-large scale experiments, and were determined to be “1 mm/min for the watch level,” “4 mm/min for the caution level,” and “21 mm/min for the alert level.” Next, the criteria for the long term were determined through a literature review and field data, and were “2 mm/day for the watch level,” “8 mm/day for the caution level,” and “56 mm/day for the alert level”.

No abstract