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一、黄土隧道工程地质分类黄土分类的方法,主要有按成因和按地质历史时代两种。按成因分为风成、冲积、洪积、坡积、残积等。有的人将风成的称为原生黄土,而其它成因的称为次生黄土。在1956年命名中第四纪(Q_Ⅱ)的黄土为老黄土,新第四纪(Q_Ⅲ)黄土为新黄土。后来又给新黄土和老黄土作了补充修正:将第四纪下更新世以前的黄土称为老黄土Ⅰ(Q_Ⅰ),中更新世的黄土为老黄土Ⅱ(Q_Ⅱ),上更新世的黄土称为新黄土I(Q_Ⅲ),现代全新世的黄土为新黄土Ⅱ(Q_Ⅳ)。按成因分类反映了黄土的形成环境条件和一定的岩性(层理性和可溶盐含量等);按地质历史时代分类,反映了黄土形成的先后和一定的岩性(坚实和松软等),这两种分类,相辅相
First, the loess tunnel engineering geological classification Loess classification methods, mainly by genesis and according to two geological history. According to the cause into wind, alluvial, alluvial, slope plot, residual plot and so on. Some people will wind known as native loess, and other causes are called secondary loess. In 1956 named the Quaternary (Q_Ⅱ) loess as the old loess, Neo-Quaternary (Q_ Ⅲ) loess as the new loess. Later, new loess and old loess were supplemented with amendments: the loess before the Lower Pleistocene of the Quaternary was called loess I (Q_I), the middle Pleistocene loess was loess II (Q_II), the Pleistocene loess Known as the new loess I (Q_ Ⅲ), the modern Holocene loess as a new loess Ⅱ (Q_ Ⅳ). According to the cause classification, the loess formation environmental conditions and certain lithology (layer rationality and soluble salt content) are reflected. According to the classification of geologic history, the sequence of loess formation and some lithology (solid and soft) These two categories, complement each other