| 摘要 |
PROBLEM TO BE SOLVED: To provide a soil improvement method using a curve drilling type chemical grouting method which can be employed to soil which is necessary to be grouted with chemicals by drilling large-depth soil having a hard part and an obstacle for a long distance.SOLUTION: A soil improvement method permanently grouts soluble chemicals by curve-drilling improvement-objective soil by using a drilling rod 32 having a tapered face at a tip. An approach part of the soil preferentially performs drilling by using a core drill type right oblique drill 40 having a core bit with a carbide chip at a tip, and comprises the carbide chip at a bit tip of the drilling rod 32. When a hard part or an obstacle exists in the soil at the drilling of a grouting part, the push-in pressure of the drilling rod is reduced to a half or smaller compared with the case that the hard part or the obstacle does not exist, a rotation number is set to a double or larger, a grouting outer pipe 46 is built into the drilling rod after the drilling, and after drawing out the drilling rod 32, a washer hose having a rotating nozzle at a tip is made to inject high-pressure water to an oblique rear from the nozzle, thus the chemicals progressing in the grouting outer pipe, and being inserted therein.SELECTED DRAWING: Figure 5 |
