The maintenance of slope stabilization works performed during the rapid economic growth period of Japan (1955—1973) has increased in recent years. During that period, slopes were mostly stabilized by shotcreting, which can protect the slope from water intrusion and erosion. Every year, some accidents take place during the maintenance of such shotcreted slopes in Japan, and such industrial accidents are likely to increase as more maintenance work is done. This paper first describes the failure of slopes covered with shotcrete at construction sites during removal of the old shotcrete. It then describes the results of centrifuge model tests conducted to simulate the slope failure.
This paper presents the application of tilt sensors to measure the movements of a slope surface and slope crest just before failure during excavation of the lower parts of the slope. The tilt sensors used here consisted of highly sensitive and accurate accelerometers, which could measure tilt angles along the XY directions. Full-scale model slopes were prepared using river sand in the laboratory; the slopes were excavated from the lower parts (toe excavations) until slope failure occurred. A gradual increment in tilt angle during the excavation and rapid increment just before slope failure were observed by the tilt sensors, verifying the applicability and efficiency of using tilt sensors to predict slope movement in actual excavation sites.
To prevent from industrial accidents caused by power presses, protective measures required by global safety standards, such as ISO12100, EN692 and EN693, shall be applied in Japanese industrial fields. The following protective measures shall be applied: 1) Standardization of safety guard, 2) Elimination of key-switch to bypass function of protective devices, 3) Blanking system for two-handed operation, 4) Effective protective devices during inching operation, 5) Guarantee of protected heights by protective devices — light curtain, 6) Protective device for sides of machine (fixed/movable guard). The inquiry into analysis has also revealed the development of new safety systems designed for servo presses, press brakes and large-sized power presses.
In recent years, many operators in Japan have been facing the problem of declining skills in occupational safety management. Operators have not been sharing adequate know-how about safety because they have had no opportunities to share skills and information. One reason for this problem is the mandatory retirement of experienced operators. Under these circumstances, the occurrence of accidents caused by insufficient safety management has increased. For this reason, in order to support inexperienced operators’ attention and skills, we suggest an operator support system using IT. The database system including information for safe operations, the assisting system for communication among many operators, and the observation system using RFID tags for identifying individual operators were proposed as a general-purpose system of safety management. New guidelines to assist decisions on safety requirement in a safe design process were also proposed to make adequate design of these systems.
Over an 11-year period (1990-2000), a questionnaire survey on work environmental management and health management was conducted on workplaces using hazardous substances, such as dust, lead, and organic solvents. Survey data were used to elucidate the management practices regarding the work environment and worker health. In several industries, a relationship was not necessarily observed between the results of work environment measurement and medical surveillance. Moreover, according to the kind of hazardous substances used, not only work environmental management but also other factors such as gender and duration of work can affect the results of medical surveillance. Careful and comprehensive assessment of the achievements of work environment and health management is necessary to prevent occupational diseases.
Two-year carcinogenicity tests in rodents are known to have the disadvantages of being expensive and time-consuming. Nowadays, carcinogenicity test models called medium-term tests exist for carcinogens. One of them is based on the concept of initiation-promotion. We have established a rat liver medium-term bioassay and rat multi-organ medium-term assay, the models showing a strong indication of potential carcinogenicity. Another is a transgenic or knock-out mice carcinogenicity model. These medium- term tests are used in addition to traditional carcinogenicity studies.
A new Japan industrial standard, JIS T8114, that is fully compatible with international standard ISO 10819 became effective in Japan in May 2007. According to the launch of this new JIS, a new vibration measurement system that fully satisfies the requirements defined in ISO 10819 was installed in the Japan National Institute of Occupational Safety and Health (JNIOSH). This paper explains the requirements defined in ISO 10819 and the specifications of the vibration measurement system installed in the JNIOSH. Several measurement results of vibration transmissibility of anti-vibration gloves available in the Japan market and others experimentally prepared for production in the near future are also introduced in this paper.