In this paper, the design of hydraulic actuating circuit of doing over-running load was performed. Generally, the counter balance valve has been used to protect over-run or free falling of acuating system. But sometimes, it makes some undesirable problems such as pressure surge or vibration. To overcome such problems and satisfy the system requirements, we suggest the hydraulic circuit actuated by servo valve. In order to verify the properness of suggested hydraulic circuit, hydraulic actuator with servo valve was modeled using ADAMS/Hydraulic which is a commercial dynamic analysis software for multi-body system. Also, the effectiveness of hydraulic actuating circuit was verified via test bed and real plant.

In order to complement the defects of a ballasted track requiring continuous maintenance and a concrete track where the initial construction cost is expensive, research on an asphalt concrete track that is easy to maintain, economical and environmentally friendly is underway. In order to investigate the safety and the applicability of the asphalt concrete track, the test construction was carried out on the Kyeongbuk line. In this study, when the Mugunghwa train runs on the asphalt concrete track, the wheel load and lateral wheel load measured through the sensors installed at the rails were analyzed. As a result of the analysis, it was confirmed that the track performance test standard was satisfied.