This paper is to develop the method of surface soil improvement by electric heating equipment. For this purpose, the electric heating systems were invented to apply to the in-situ soil. Iaboratory tests were done to study the behaviors of sea clays by eletric heating. In lab tests, two different heating temperatures, 70℃ and 110℃, were applied to the saturated clays to examine the relationship between evaporation and compaction. In addition, trafficability was analyzed to the heated by applying cone penetrometer to the heated clays Furthermore, in-situ tests were conducted to analyze the range of soil improvement and strength variations. The temperature changes in field were measured and they were compared with those of the commercial program (Temp/W). Also, the bearing capacities of electrically heated field were tested by PBT (plate bearing test). Several conclusions were derived from the results of the numerical analysis and tests (lab and field). The improvement ranges and strength variations of electrically heated soil depended on the heating temperature and time. If the heating temperature is more than 100℃ evaporating the ground water, the bearing capacity and settlement increased rapidly. The bearing capacities of in-situ soil increased more than 3 times, and heated soil emitted a lot of vapors. The soil around electric heater was sintered completely, and its range was almost 20 cm.

When diagnosing damage to high-rise buildings during earthquakes, it is necessary to measure the displacement of each story. However, with respect to accuracy and cost, it is most reasonable to convert acceleration into displacement. In this study, shake table testing was carried out to verify the conversion methods, converting the acceleration data measured in a high-rise building into velocity and displacement. In the shaking table test, the displacement of a 10-story model building under strong motion was measured using high-speed imaging devices. High-speed images were taken at 1000 frames per second, reflecting the dynamic behavior of the model building. Then, this displacement was compared with the displacement obtained by processing the acceleration data. This study applied three methods for correcting and converting acceleration into velocity and displacement. Method 1 used the transfer function, H2ω, which reflects the dynamic characteristics of the system. The displacements converted by this method showed the lowest accuracy, because the transfer function depends on the dynamic characteristics of the structure. Method 2 used the cosine Fourier transform for baseline correction, and the discrete input data are calculated as the sum of the cosine functions. Method 3 used the least-squares fitting in the first step to remove the linear drift in the acceleration and applied the high-pass Butterworth filter. The displacements converted by Method 2 were the most reliable, and were close to the displacements measured in the shaking table test. However, the response of high-rise buildings is affected by low- and high-frequency noise. It is necessary to further investigate the limitations and applicability of the conversion methods for providing reliable displacement of the building.

In this research, stainless steel and heat-shrinkage tube were used for new TDR sensing line to solve the problems of ordinary TDR system. The new TDR line improved the sensitivity of water content and endurance, and reduced the data noise. The saturation degree test and acryl model test were done by revised TDR sensor. From the results, without additional data filtering and quantitative analysis, the raw data were separated into 3 zones; saturated, unsaturated and dried zones easily. In addition, the revised TDR sensor was installed in large-scale embankment model to perform the seepage test. The raw data of the model tests showed the distributed seepage behaviors and separated zones clearly, which were almost the same tendencies as the lab test results.

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