青藏铁路多年冻土工程地质特征及其评价

青藏高原多年冻土是地质历史时期高海拔寒冷气候条件下的产物,也是青藏铁路建设的三大难题之一;而多年冻土工程地质特征及其评价工作是作出合理、可靠的工程设计的基础。结合青藏铁路沿线多年冻土区的15个地形地貌分区,在青藏铁路多年冻土区选择了70个典型断面进行了地质勘查,采用地质钻探和室内试验相结合的方法,研究了各区的工程地质特征并对其工程地质类型进行了评价。研究表明:青藏铁路多年冻土区冻土类型多样,高含冰量冻土、厚层地下冰广泛分布,不同区段地温差异性较大,工程地质条件复杂多变,良好、一般、不良和极差的工程地质区段交错分布。

ENGINEERING GEOLOGICAL CHARACTERISTIC AND EVALUATION OF PERMAFROST GROUND ALONG QINGHAI-TIBET RAILWAY

Qinghai-Tibet permafrost is one of the productions of high altitude and iciness weather in the geological period,and also is one of the three puzzles in the Qinghai-Tibet Railway construction.Moreover,the work of engineering geological characteristic and evaluations for the permafrost ground is a foundation for a reasonable and dependable engineering design.Based on these reasons and the 15 types of geomorphic distributions along the Qinghai-Tibet Railway,70 typical profiles in the study area are chosen to carry out geological investigation.We use the methods combining geological drilling in the field and laboratory experiments and analyses.We examine the geological characteristics of each section and evaluate engineering geological types of each section.the investigation shows: it has many types of permafrost in Qinghai-Tibet permafrost areas,extensive distribution of permafrost of high ice content and thick ground ice,different ground temperatures in different sections,and the complex geologic structures of the project,interlaced distributions of engineering geological sections of different types.The results can provide the foundation for control disasters along Qinghai-Tibet Railway in use period.They can also be used as a reference for railway construction of the similar regions.