Since earth pressure changes depend on soil depth and surrounding situations, the construction of earth retaining temporary structures should be able to measure the change of the earth pressure and cope with the changes. When the underground excavation and construction of earth retaining temporary structure repeatedly occur, the excavation should be less interfered by the earth retaining structure. A PS synchronize wale measures the horizontal deflection of the structure and generates tension on the wire rope by controlling the hydraulic cylinder so that the wale is in safe range. Since the horizontal load is canceled by pre-stress bending moment, the number of struts the horizontal load is reduced making the excavation interference is small. We evaluated the horizontal deflection of the PS synchronize wale with increasing tension and verified that the deflection of the PS synchronize wale can cancel out the horizontal load in the safety range of 5 mm. This occurs through a universal testing machine experiment simulating earth pressure. We are in the process of applying the PS synchronize wale to a test bed and expect it to be safer and more efficient than existing methods.

In this study, a numerical analysis on the impact response of HHA (High Hardness Armor Plate) sequences under a 7.62 mm projectile impact was performed to obtain the fundamental design data for a combat-vehicle platform. Recently, the ballistic-protection levels for combat vehicles have increased, and ballistic-protection designs should now be able to deflect multi-hit projectiles. To study the ballistic-impact characteristics, armor-plate sequences of one or two layers with a gap of 0 mm to 2 mm between the front and rear plate were defined under the same weight and thickness. For the certification of the reliability of the numerical model, ballistic tests and an analysis of the single plate under the 7.62 mm projectile impact were performed and analyzed. On the basis of a valid numerical model, a numerical analysis was performed and analyzed. Lastly, it was proved that the performances of the two-layer sequence with the 2 mm gap regarding the impact-response acceleration, deflection efficiency, and penetration depth are the highest.