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Nakashima, Satoru (Osaka University) | Isono, Youco (Eight-Japan Engineering Consultants Inc.) | Kimura, Takayuki (Eight-Japan Engineering Consultants Inc.) | Kanaji, Junpei (FUSO PRECISION Co. Ltd) | Shukuin, Yasuaki (FUSO PRECISION Co. Ltd) | Takeda, Naoto (FUSO PRECISION Co. Ltd) | Yoshida, Yukinobu (Osaka University) | Hamasaki, Tomohiro (West Nippon Expressway Co. Ltd.) | Watanabe, Daisuke (West Nippon Expressway Co. Ltd.) | Tsutsumi, Hiroshi (West Nippon Expressway Co. Ltd.) | Kawakami, Kunji (West Nippon Expressway Co. Ltd.) | Saeki, Toru (West Nippon Expressway Co. Ltd.)
Abstract Spectro-colorimtery and near infrared (NIR) spectroscopy has been applied to rocks for evaluating non-destructively their compressive strength. b* values (yellow) of Paleogene granite core samples showed a good correlation with the uniaxial compressive strength (UCS) (156–97 N/mm), while those for Ryoke granodiorite core samples with less strength (71–0.2 N/mm2) showed only slight changes. NIR band areas around 1450 nm (OH) and 1950 nm (HO) indicated two different quasi-linear relations in logarithmic diagrams against the UCS. Hydration of feldspars in these granitic rocks is considered to be a good indicator of rock strength. Colors and water contents by these spectroscopic methods showed also positive relations with UCS estimated by the point load test on granodiorite porphyry, welded tuff and sandstones samples. A handy portable spectro-colorimeter (PRISMO MIRAGE) has been developped for measuring visible reflection spectra and color values of materials on field sites. We applied this method for the measurements of colors (L*: white-black, a*: red-green, b*: yellow-blue) of rock masses at highway construction sites. These color values were compared with the uniaxial compressive strength of rocks estimated from on-site Schmidt Rock Hammer test. The results on igneous rocks (welded tuff and granodiorite porphyry) at HigashiKyushu highway construction sites at Miyazaki, Japan indicated fairly good relationships among a* (red) and b* (yellow) with the rock strength. However, colors of sandstones at ShinMeishin highway construction sites at Osaka, Japan showed worse correlations with the rock strength and other evaluations such as water contents on-site by handy NIR spectrometer is necessary. The rock quality and its degradation can be evaluated at least partly by this on-site spectroscopy.
ABSTRACT: The relationships between a long period harbor oscillation and ship motions induced by long period waves were investigated through field observations and numerical calculations. The field observations for the water surface oscillation and ship motions were carried out at Hosojima Port, Miyazaki, Japan, from August to September in 1997. The field data showed that the long period waves were amplified in the port and they induced large ship motions which caused the interruption of cargo handling. The numerical calculations based on a boundary element method were also carried out to investigate the effectiveness of an offshore breakwater proposed for a counterrrieasure against long period waves in addition to protecting inside the harbor against wind driven short period waves. Although the damping effects of the wave height by the offshore breakwater tended to become less for longer period of waves, the effectiveness of the offshore breakwater was also observed in long period waves. INTRODUCTION The interruption of cargo handling has been reported at several major ports in Japan(CDIT,1998). In Hosojima Port, sixteen" cases of obstruction w"ere reported in 1996. These obstructions included the interruption of cargo handling caused by large ship motions and sometimes by breaking of mooring ropes. A main cause of these obstructions was considered to be a long period harbor oscillation induced by long period waves, because a surge motion with a period from 100 to 200 seconds was frequently reported when the interruptions occurred (e.g., Hiraishi,1997, Suganuma etiat.,1995). In this study, the field observations were carried out to investigate the relationships between the long period harbor oscillation and ship motions induced by long period waves. The numerical calculations on resonance in harbor were also carried out to investigate the effectiveness of an offshore breakwater proposed for a countermeasure against long period waves.
Nakazono, Takefumi (Kagoshima University) | Kunitake, Masato (Miyazaki University) | Kondo, Fumiyoshi (Miyazaki University) | Inagaki, Hitone (Kagoshima University) | Nakazawa, Takao (Miyazaki University) | Kikumura, Tadayoshi (Ready-Mixed Concrete Association of Miyazaki) | Saito, Masaki (Crown Engineering Co. Ltd.) | Kakuda, Itsuro (Nihon Suiko Consultant Co. Ltd.)
ABSTRACT In order to predict thermal cracks in coastal concrete structures, it is necessary to have a precise grasp of the hysteresis of temperatures generated by heat of hydration. Therefore, the temperatures solved by three-dimensional finite element analysis using the Galerkin method were compared with· the measured temperatures, but it was not possible to make a better approximation of their hysteresis. Accordingly, the interior concrete temperatures were calculated using a new equation that we have proposed instead of an empirical equation expressing the characteristics of heat generation in concrete structures. The hysteresis of the calculated and measured temperatures showed good agreement. INTRODUCTION In order to predict thermal cracks in coastal concrete structures, it is necessary to have a precise grasp of the hysteresis of temperatures generated by heat of hydration. Although a large number of studies; have examined concrete temperature for a period of curing of mass concrete structures, little attention has been given to the interior temperature generated by heat of hydration in concrete structures of small volume. Two Sets of data averages for temperature and humidity were obtained from meteorological records of the last ten years in Miyazaki, Japan, and were adopted as the environmental conditions for the concrete specimens. The interior concrete temperatures were measured by a thermocouple sensor embedded at the center of each specimen, which was cured at a constant 30 °C and 80% humidity as summer conditions and at 5°C and 50% humidity as winter conditions in the laboratory (Nakazawa et al, 1987). Then, the hysteresis of temperatures generated by heat of hydration at the center of the concrete specimens was simulated by a three-dimensional unsteady heat conduction problem in a Cartesian coordinate system using finite element analysis with the Galerkin method. The partial differential equation for unsteady heat conduction in an isotropic solid body in the Cartesian coordinate system was solved using a convection boundary condition.