以标贯试验为依据的砂土液化确定性及概率判别法

核电厂址非基岩场地的地基液化问题是核电厂选址的关键问题，亟需建立核电厂址地基液化判别方法。回顾了以标贯试验和地表峰值加速度为依据的砂土液化判别方法的演化历史，依据Idriss-Boulanger确定液化临界曲线的基本方法，提出了确定液化临界曲线的基本原则，分别依据美国液化数据库、中国抗震规范液化判别式所用的液化数据及综合两者的液化数据资料，给出了相应的液化临界曲线，验证了液化临界曲线的位置对不同的细粒含量、有效上覆压力、现场试验方法的液化数据的合理性，分析了测量或估计土层循环应力比和修正标贯击数各种因素的不确定性对液化临界曲线的敏感性，结果表明：所提的液化临界曲线不易受各种因素的影响。利用Monte Carlo模拟、加权最大似然法和加权经验概率法，给出了液化临界曲线的名义抗液化安全系数与液化概率的经验关系式及概率等值线，并对核电厂Ⅰ类、Ⅱ类和Ⅲ类抗震物项地基，给出了相应的液化临界曲线。

Deterministic and probabilistic triggering correlations for assessment of seismic soil liquefaction at nuclear power plant

Seismic soil liquefaction problem in the soil site of nuclear power plants is a crucial point for the nuclear power plant siting. Therefore, it is urgent to develop a seismic soil liquefaction assessment procedure suitable for the soil site of nuclear power plants. The standard penetration test (SPT) and peak ground acceleration (PGA) based assessment method of soil liquefaction potential is reviewed. The basic principle to determine liquefaction triggering curve is proposed. Three corresponding liquefaction triggering correlations are derived respectively from the Idriss and Boulanger liquefaction case history database, the database of Chinese Code for Building Seismic Design and the two combined databases to reduce the possibility of mistaking liquefaction data points as no-liquefaction data points. The positions of the derived liquefaction triggering correlations are verified with respect to many factors including fines content, overburden stress and standard penetration test (SPT) procedures. In addition, the sensitivity of the database’s interpretation to a number of aspects and components of the analysis framework is examined. The results show these factors have a slight effect on the position of the proposed liquefaction triggering correlations. At last, the relationship among the nominal factor of safety and the probability of liquefaction as well as the probabilistic contours for the proposed liquefaction triggering correlation is given on the basis of Monte Carlo simulation, the weighted maximum likelihood technique and a weighted empirical probability approach. The soil liquefaction triggering correlations are proposed for the soil sites of seismic design categoryⅠ, Ⅱand Ⅲ of the structure, system and component of nuclear power plants, respectively.