| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem caused by a water pipe in a freezing pipe used in a freezing construction method. SOLUTION: This freezing pipe 1 is provided with a partition wall 61 at the tip of an outer pipe, and composes a selector valve 6 of the partition wall 61 and an inner pipe 3. The selector valve 6 can communicate the tip part of the inner pipe 3 selectively with the outside of the partition wall 61 of the outer pipe 2 and with the inside of the partition wall 61. With the changeover of the selector valve 6, the inner pipe 3 is used as a pressure water supply pipe when driving the freezing pipe 1 into the ground, and pressure water is jetted from the tip of the outer pipe 2 to assist driving of the outer pipe. When the freezing pipe 1 is put in freezing operation, the inner pipe 3 can be used as a brine supply pipe. A conventional water pipe 11 is thereby dispensed with to solve a problem in installing the water pipe 11 and a problem caused by the water pipe remaining in the outer pipe 2 in refrigerating operation. COPYRIGHT: (C)2004,JPO
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