中国西南山区第四纪冰川堆积物工程地质分类探讨

中国的大陆冰川堆积物几乎都属于巨粒土或块石（漂石）土、碎石土，但因复杂的物质组成和组构特征，各地或同一地区不同成因类型（冰碛、冰水）的堆积物具有极为不同的工程地质性质，其地质体稳定性和地质灾害的易发性存在着显著的差异。我国已有的工程分类框架不能满足当代冰川堆积物甚至其他碎石土（巨粒土）的工程地质和地质灾害研究的需要。中国西南山区冰川堆积物的物质成分、细观结构等的野外调查和室内测试分析结果表明，冰川堆积物的物质成分和组构特征主要表现为：颗粒组成的不均一性和多元性、组构单元的双元性、结构的无序性和胶结性等。冰川堆积物的物质成分和组构特征与其工程性质具有密切的关系，是冰川堆积物工程地质分类的基础。本文探讨了中国西南山区冰川堆积物的工程地质分类问题，提出基于胶结程度和粒度组成的二级分类方案，对冰川堆积物及其他块（漂）石土的工程地质研究和工程实践具有一定指导意义。

ON THE ENGINEERING GEOLOGICAL CLASSIFICATION |OF QUATERNARY GLACIAL DEPOSITS IN SOUTHWESTERN MOUNTAIN AREA OF CHINA

A majority of the Quaternary glacial deposits in China  belong to either coarse-grained soil (erratic stone soil) or gravel soil. However, the engineering properties are different for glacial deposits in different areas or forming by different processes in  a same area.  It is because of the complex material composition and fabric characteristics of the deposits.  The stability of geological bodies and geo-hazard susceptibilities are also significantly dissimilar. The existing relevant standards of engineering classification  are not suitable to the need of future investigation on  engineering geology and geo-hazards of glacial deposits. The field investigations and laboratory tests have shown that the glacial deposits have the following characteristics: inhomogeneity in particle size, dual elements in fabric, out-of-order and cementation in structure, etc. All the above characteristics have some closed relationships to the engineering properties of glacial deposits. In this paper, the engineering geological classification for the glacial deposits is discussed. A two-level classification scheme  is presented and includes the evaluation of cementation, meso-structure and composition size.  The schem can be considered as a guide to  engineering practice and character study of the glacial deposits.