当用于需要对具休结果进行费用比较的地震风险分析时,逻辑树是有意义的;但在地震灾害分析中,用其确定工程上使用的地震地面运动时,逻辑树则是失败的。失败的原因在于错误地试图给出带有个人色彩且不确定的可信度值,因为这些数值几乎象爱好或口味一样,无法进行测试。因此,其结果是一些复杂而混乱的个人印象,但工程上需要的是一些尽可能基于实际证据的数值。 A logical tree makes sense when used in seismic risk analysis that requires cost comparisons of disagreement outcomes; however, in seismic hazard analysis, the logic tree fails when used to determine seismic ground motions used in engineering. The reason for the failure was to mistakenly try to give believable values ​​with uncertainty and personal color, as these values ​​were almost as good as taste or taste and could not be tested. As a result, the result is a complex and confusing personal impression, but what is required of engineering is some numerical value that is based, as much as possible, on actual evidence.