| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain sufficient shielding efficiency even to an upper half, an inclined face part or narrow part of a tunnel having an arch-shaped upper part, restrict the amount of expensive bentonite as little as possible, thereby achieving an inexpensive operation, and quickly and easily finishing the operation. SOLUTION: A lateral pile 12 is provided in a rock layer 10, and a hole 13 for storing a waste is formed at a bottom part of the lateral pile 12. A bentonite-mixed earth with gravel is compressed to a bottom face of the lateral pile 12 to cover an upper part of the hole 13, thereby forming a compression part 1. The earth is composed of gravel (Gmax =5-20mm), sand and bentonite by 50:20-40:30-10 (dry weight %). A block 2 formed by compressing the bentonite- mixed earth with gravel is piled on the compression part 1. The bentonite-mixed earth is sprayed to a spray part 3 such as between an inner face of the lateral pile 12 and block 2, etc.</p> |
