Automatic Preassembling System for Reinforcement of Underground LNG tank

A new automatic reinforcement preassembling system introduced in a underground LNG tank construction project at the Sodegaura Plant of Tokyo Gas is discussed in this chapter. The system incorporates a curved bar setting apparatus and a straight bar setting apparatus for arrangement of reinforcing bars, a bar arrangement support base for holding reinforcing bars, an automatic binding apparatus, and a control apparatus, and is constructed in a manner for assembly of reinforcing bar meshes through certain procedures. Each bar setting apparatus(one unit for straight reinforcing bars, the other for curved reinforcing bars) moves sequentially to designated locations to arrange reinforcing bars on a frame. After arranging reinforcing bars, the bar binding machine moves to the specified places and ties the interesting point of the reinforcing bars. The binding machine No.10 (3.23mm) annealed wire of general type.The system is capable of handling 60 each of straight D41 bars, length 10.5m, and curved bars of length 10m. The maximum dimensions of preassembled units are 12.7 X 12.4m. the procedure for preassembly can be changed simply by programmable controller in accordance with pitch and size of arranged bars. As a result of application in the field, a reduction of manpower by approximately one-sixth of conventional requirements was achieved and contributions were made to improvement of the work environment.