| 摘要 |
PROBLEM TO BE SOLVED: To integrate a reinforcing-bar distortion detection structure capable of detecting clod movement on a slope with high sensitivity into a cylindrical reinforcing-bar when performing reinforcing-bar insertion work using the cylindrical reinforcing-bar.SOLUTION: In a hollow sensor rod 5, a small diameter part 7 and a large diameter part 8 for forming a little gap to an inner surface of a cylindrical reinforcing-bar 1 are formed alternately. The hollow sensor rod 5 is inserted into the cylindrical reinforcing-bar 1 and both ends of the hollow sensor rod 5 are fixed to the cylindrical reinforcing-bar 1. A distortion gauge 13 is affixed on an outer circumferential surface of the small diameter part 7 of the sensor rod, and a lead wire of the distortion gauge 13 is put from a hole which is opened in the small diameter part, into the sensor rod and pulled out of an apex of the cylindrical reinforcing-bar 1. When the cylindrical reinforcing-bar is bent and deformed by movement of clod, the sensor rod is bent and deformed in accordance with the bending deformation of the cylindrical reinforcing-bar by action of the large diameter part 8 which forms a little gap to the inner surface of the cylindrical reinforcing-bar 1. In that case, the outer circumferential surface of the small diameter part is distorted larger than the outer circumferential surface of the large diameter part, such that the bending deformation of the cylindrical reinforcing-bar 1 can be detected with high sensitivity by the distortion gauge affixed to the outer circumference of the small diameter part. |
