采用数理统计与概率论方法,对历史渍坝事件进行了统计分析,结果表明:大坝总体失效概率为10^-4的失效概率数量级;混凝土坝溃坝相对比率与土石坝相接近,但堆石坝的大坝结构失效概率最高,较其他坝型几乎高一个数量级;混凝土坝设计使用年限虽然长,大坝结构失效概率处在平均水平,拱坝的失效概率略高于平均水平;低坝是溃坝的重灾区,30m以下中小型水库占溃坝数的70%以上,但大中型水库带来危害性更大,甚至是毁灭性的;大坝结构失效原因是多方面的,可划分为17类,相应失效概率亦不同,归结起来有超标准洪水(泄洪能力不足)、工程(尤其坝体)结构强度不够、以及人为和地基条件恶化等方面,最终体现于工程承受的荷载超过结构发挥的抗力。
We use mathematical statistics and probability theory to analyze historical dam -break incidents. It is shown that the general dam - break probability is at the magnitude of one ten - thousandth ; darn - break probability of concrete dam is close to that of earth - rock dam ; the structural failure probability of rock fill dam is the highest and its dam - break probability is one order of magnitude higher than that of concrete dam and earth - rock dam ; the structural failure probability of concrete dam is at average level even if it has long design life - span ; the failure probability of arch dam is slightly higher than average probability of dam failure; the failed dams are mostly small dams, in which, the failed dams with dam height lower than 30 m account for 70% of dam - break incidents; the failure of large and medium reservoir bring about more disasters, even fatal disaster. The failure types of dams can be divided into 17 categories with different probabilities. The causes can be summarized as follows: insufficient discharge capacity, inadequate structural strength of dam body, artificial cause, clam foundation deterioration. In general, the fundamental cause is that the dam bearing load is larger than dam bearing capability.