送交者: skipper3 于 2005-7-22, 17:04:23:
回答: 一两百年足够了。科技发展到那时，也许大坝都没用了。造太结实了纯属浪费。 由 Enlighten 于 2005-7-22, 16:19:25:
on how you look at the risk. Say if you think a 1% of failure means the dam is broken while I say 5% of failure means broken, then to you a dam will last only 50 years if the risk of being broken is 1% after 50 years, but to me it last much longer because such risk will not reach 5% until many years later.