Single and multiple regression models to estimate the compression index of marine clay in coastal areas in Korea were investigated based on soil property data from more than 1200 consolidation tests on undisturbed samples. Site-specific empirical correlations were proposed to estimate the compression index in terms of both single and multiple soil properties. The proposed regression equations were then compared with the existing empirical equations. It was found that the compression index predicted by a simple linear regression model involving the natural water content, natural void ratio, and liquid limit can reasonably evaluate the real soil compression index. These regression equations may allow a preliminary estimation of the ground settlement for marine clay. It was also recognized that the applications of empirical equations suggested in previous studies result in large uncertainties in estimating the compression index of marine clayey soil in the coastal zone in Korea.Key words: settlement, compression index, regression, statistical analysis, consolidation.

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In the present study, the influences of load on the abrasive wear properties of silica-filled epoxy resin composites were investigated at ambient temperature. The friction coefficient, wear rate and specific wear rate against SiC abrasive paper were determined experimentally. The sliding wear tests of the materials demonstrated that the friction coefficient and the wear rate of silica filled epoxy composites were lower than those of the pure epoxy. The cumulative wear volume tended to increase nonlinearly with increase of sliding distance and depended on diameter of the silica particle for all these composites. The friction coefficient and wear rate were raised substantially with an increase in applied load.

In this study, microstructure and wear behavior of thermally sprayed Fe-based alloy coatings were investigated. Fe-based alloy coatings were formed on a carbon steel substrate and then heat-treated at temperature of 700 oC for 20 minutes. Dry sliding wear tests were performed using the sliding speeds of 0.4 and 0.8 m/s, the applied loads of 3 and 6 N. Microstructure and wear behavior of as-sprayed and heat-treated Fe-based amorphous coatings were studied using a scanning electron microscope(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD).

In this study, the mechanical properties of silica-filled epoxy resin composites with average silica particle diameter of 6-33m were investigated at ambient temperature and pin-ondisc friction test was conducted for this. Experimental results demonstrated that mechanical properties such as flexural strength, flexural modulus and critical stress intensity factor depend on average particle diameter. The flexural strength decrease with increase of particle size whereas the critical stress intensity factor increases with increases of particle size. Wear rates of silica-filled composites are below a half those of unfilled epoxy. Fracture surface analysis was discussed based on SEM examination.