Lock Up Devices / Shock Transmission Units
TechStar Lock-Up Device (LUD) sometimes referred to as Shock Transmission Units (STU), create a rigid link at an otherwise moveable connection. During any sudden load, seismic, braking, train acceleration, ship collision or any other force acting on the bridge that would cause the bridge to move suddenly, the LUD becomes a rigid link and the forces are then transmitted through the structure. The concept is to share the load throughout all piers and abutments. By temporarily creating a rigid link where expansion and contraction normally occur, the bridge can be modeled as completely fixed. In continuous bridges the fixed pier no longer must resist the longitudinal forces as all other piers equipped with LUDs would be fixed during this loading condition. In accordance with AASHTO, all testing is done by independent laboratories to assure the performance of the device.
Additional Information:
Carquinez Installation Photo 1
Carquinez Installation Photo 2
Carquinez Installation Photo 3
Carquinez Installation Photo 4
LUD Installation on IRR Cable Stay, Bangkok, Thailand
LUD Installation on Quebec Bridge, Quebec, Canada
LUD Installation on CN Railway Bridge, Winnipeg, Manitoba, Canada
LUD Installation on Paksey Bridge, Bangladesh
Shock Transmission Unit PPT Presentation (English / Chinese)