中文摘要：

黄土液化的判别是工程界长期存疑的问题。本文基于不同黄土场地的现场标贯试验、波速测试和试样的室内动三轴试验研究以及《兰州市区建筑抗震设计规程》（DB62／T25—3037—2006）使用反馈情况，提出了饱和黄土场地液化的工程初判和详判指标与方法：（1）地层年代、粘粒含量、塑性指数、剪切波速、土层埋深条件等可作为饱和黄土场地液化初判的指标；（2）国家《建筑抗震设计规范》（GB50011—2010）中基于标贯击数的液化判别公式和液化指数计算公式适用于饱和黄土地基的液化判别和液化程度评价，但黄土液化判别的标贯击数基准值需要修正；（3）对应于设防加速度0．1g、0．15g、0．2g、0．3g、0．4g下饱和黄土液化判别的标贯击数基准值应分别为7、8、9、11、13，显著小于砂土液化判别的相应值。目前该判别方法已被纳入《甘肃省建筑抗震设计规程》（DB62／T25—3055—2011）。

英文摘要：

Loess liquefaction is a disastrous phenomenon which should be carefully treated to reduce the risk. But the relative lacking of both site study results and engineering experience makes it difficult to evaluate liquefaction potential of loess of construction sites. Through many studies carried out since 1990＇s, the understanding for loess liquefaction is improved substantially. As a result, to incorporate of these studies in seismic code became urgent, but at the same time, new proposals on loess liquefaction often face scrutiny from engineers. In order to resolve the difference between laboratory studies and information obtained from field, the two approaches must be combined and any proposal on evaluation of loess liquefaction should at least sound reasonable by applying field test data, which is the backbone for geotechnical analysis. Based on previous studies, this study carried out experiment in laboratory to get understanding of loess liquefaction behavior and the main factors that determined whether the loess sample wound liquefy or not. Then using feedbacks from engineers on accept method for loess liquefaction evaluation, field data of saturated loess site were collected, and the liquefaction evaluation method recommended in Chi- nese ＂Code for seismic design of buildings＂ （ GBS0011 -- 2010 ） （ referred as ＂national seismic code＂ } was examined to validate its suitability for loess liquefaction. Through all these efforts, it is found that the liquefaction of loess cannot be properly evaluated by using the current liquefaction potential evaluation method in national seismic code. And the laboratory test is good at providing preliminary evaluation information on weather loess will liquefy or not under certain seismic in- tensity. For detailed evaluation of loess liquefaction, field data interpretation is more reliable. Based on these understandings, the proposed method on loess liquefaction is a two stage evalua- tion： 1） for Preliminary evaluation of loess liquefaction, the age, clay co