抄録
The evaluation method of design of embankment is proposed on the basis of cost functions which are formulated in relation to its probability of failure. Four design alternatives are investigated. That is, (1) alternative A1 is to increase the number of laboratory test in order to get more informations on soil properties, (2) alternative A2 is to decrease the slope gradient, (3) alternative A3 is to increase the resisting moment with a counterweight fill and (4) alternative A4 is to increase the shear strength by improving the poor ground with sand compaction piles.The proposed cost functions and the numerical examples show that the alternative A4 gives the minimum total expected loss when the cost purchasing land is very expensive, but that the alternatives A1, A2 and A3 tend to be selected for design when the land cost is not so expensive. Further, they show that the acceptable value of the failure probability for design should be reduced when the anticipated failure loss is considered very expensive.
