| 摘要 |
PROBLEM TO BE SOLVED: To design a cushioning material on the basis of appropriate evaluation of the degree of maximum stress generated to the cushioning material in construction. SOLUTION: In this design method of the cushioning material in curve jacking of a jacking pipe, the stress degree to the compressibility of the cushioning material is computed from the relation between the stress degree and compressibility of the cushioning material, and the thickness of the cushioning material is determined so that the maximum stress degree of the cushioning material is the allowable stress degree of concrete. A relational expression of the stress degree and compressibility of the cushioning material is obtained by making experiments for every cushioning material to obtain an approximate expression from experimental values, and the stress degree to compressibility is computed from the expression. The cushioning material is subdivided in parallel, and the area (a) and compressibility of every section of the subdivided cushioning material are obtained to determine the stress degreeσc of every section from the compressibility. The integrated value of the product of the area and stress degreeσc of every section is made the thrust of the jacking pipe, and the maximum stress degree at that time is made the maximum stress degree generated to the jacking pipe in that thrust. COPYRIGHT: (C)2006,JPO&NCIPI
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