Abstract:

As one type of important Quaternary deposits distributed in Northwest Yunnan, West Sichuan and Tibet of China, the study of the engineering properties of glacial deposits and their related geo-hazard, as well as engineering problems, have attracted the attention of many engineers. Based on investigation of the moraine and outwash deposits in above regions, the authors find that they are very complicated Quaternary deposits with special composition, structure and properties. Their engineering properties are mainly related with the composition of the gravel and the filled material. e.g. the moraine and outwash deposits distributed in limestone areas can turn into rocks, named moraine rock or outwash rock, caused by calcite cementation, which has a uniaxial strength from 10.94 MPa to 14.22 MPa. This paper has presented the types and distribution characteristic of the Quaternary glacial deposits on the west side of the Yulong Mountains, which was an important task for the selection and optimization of the Yunnan-Tibet railway line in Northwest Yunnan. Based on lab test of physics and mechanics, the results of engineering properties of moraine/outwash rocks, including the cement composition and their cementation, stability in water, mechanical property, and sound spreading velocity, etc., have been reported, which can not only enrich the research contents of rock mechanics, but also have important practical value for railway construction and water power development in mountain regions.

Key words: glaciation, moraine rock, outwash rock, engineering geological property, Yulong Mountains