| 摘要 |
PROBLEM TO BE SOLVED: To provide a determination device and a determination method in which an injection nozzle for injecting a jet flow (jet) having a long ground cutting distance is inspected in a stage prior to introducing a large diameter jet mixing method into a construction site, and a determination is made whether or not the inspected injection nozzle is a defective product.SOLUTION: A nozzle being an inspection object is attached to an injection port and a jet is injected from a jet injection device 1. The measurement result measured by a pressure sensing unit 2 when the jet collides to a pressure sensing unit 2 is processed by a control device 10 (e.g., a computer). A decision is made that the nozzle being the inspection object is a non-defective product when a first ratio is a first predetermined value or higher, a second ratio is a second predetermined value or higher, and a third ratio is a third predetermined value or higher.SELECTED DRAWING: Figure 1 |
