核设施勘察中抗震Ⅰ类物项饱和砂土地基的液化判别

Liquefaction Evaluation of Saturated Sand Foundation for Category Ⅰ Items of Earthquake Resistance in the Survey of Nuclear Facilities

把多种方法应用于某核设施勘察中,针对抗震Ⅰ类物项饱和砂土地基液化判别,认为现行核电厂抗震设计规范对液化判别的安全度与核设施破坏的严重后果不匹配.学者建议的基于SPT和剪切波速液化判别方法的安全裕度高于现行抗震规范,建议对抗震Ⅰ类物项饱和砂土除按照规范进行液化判别外,应采用最新的液化判别研究成果进行对比分析.根据实际工程情况,建议抗震Ⅰ类物项液化概率控制值可由4%调整到8%、名义抗液化安全系数可由1.45调整为1.2.对基于剪切波速的液化判别曲线,指出了在特定条件下会出现不符合常理的计算结果,应结合地质资料综合判定是否液化.

A variety of methods are applied to the survey of a nuclear facility.According to the liquefaction evaluation of saturated sand foundation of category I items,the safety of liquefaction evaluation in the current earthquake resistance design specification is not comparable with the serious consequences of the destruction of a nuclear facility.The safety margin proposed by scholars based on the SPT and shear wave velocity liquefaction evaluation method is wider than the current seismic specification.It is suggested that the latest research results of liquefaction evaluation should be used for comparative analysis in addition to the liquefaction evaluation in accordance with the specification.Based on the actual engineering,the liquefaction probability control value of category I items for earthquake resistance is proposed to be adjusted from 4% to 8%,and the nominal anti-liquefaction safety factor is proposed to be adjusted from 1.45 to 1.2.For the liquefaction evaluation curve based on shear wave velocity,there will be abnormal calculation results under certain conditions,and whether the sand is liquefied or not should be determined comprehensively with geological data.