| 摘要 |
PURPOSE: A front device for the grouting purpose is provided to execute the ground drilling work and the chemical injection work and to prevent the counterflow of the injected chemicals. CONSTITUTION: The front device for the grouting purpose contains a bit(100) perforating a hole, an outer pipe(200) coupled to the upper part of the bit(100) to form an inflow passage(201) inward, and an inner pipe interposed to the outer pipe(200) to form an injection passage inward. Wherein the inner pipe contains an upper pipe(330), a connection pipe coupled to the upper pipe(330), and a lower pipe(310) fitted to the connection pipe to be slidable and provided with a counterflow prevention pipe(400).
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