It is estimated that there are 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt, and 100 of them cause damage. 據(jù)估計(jì)，世界上每年可監(jiān)測(cè)到的地震有500，000次，其中100，000次地震是可以被人類(lèi)感覺(jué)到的，這100，000次地震中又有100次是有可能造成破壞的。
Determination of detectable flaw size is the requirement for establishing maintenance plan, and it is an important basis for analyzing the damage tolerance and durability. 確定維脩檢測(cè)中可檢裂紋的尺寸是制定維脩大綱的需要，同時(shí)也是損傷容限耐久性分析所必須的重要依據(jù)。