川藏公路冷曲河段工程地质条件差,地质灾害频发,严重影响行车安全和公路改扩建工程。深入系统地认识冷曲河廊道工程地质条件是保障工程建设和交通安全的科学基础。本文在工程地质条件分析的基础上,依据工程地质条件的差异进行了定性的工程地质分区与评价;选取坡度、地形起伏度、岩土体内摩擦角与粘聚力、断裂密度与活动性、外动力作用、水文地质条件等作为评价指标,利用层次分析法确定指标的权重值;采用工程地质指数与集对分析模型分别对工程地质区及亚区进行定量评价;将定量评价结果与定性评价结果进行对比并用公路灾害线密度进行验证,得出了较为合理的工程地质分区与评价结果;将研究区工程地质条件分为3个区和6个亚区,并编制了廊道工程地质分区图,结果可为川藏公路工程整治及防灾减灾提供参考。
The engineering geological condition along the Lengqu River section of Sichuan - Tibet Highway is ex- tremely poor and complicated. Rich geological hazards developed along the Lengqu River section is posing a direct threat to the Highway safety and compromising improvement project of the Highway. It's extremely imperative to in- vestigate the engineering geological condition for the sake of the Highway improvement project. By analyzing engi- neering geological conditions, a qualitative engineering geological evaluation and zonation was completed in terms of differences in engineering geological conditions at highway sections; Some governing factors-slope, surface rolling, internal friction angle and cohesion of rock, density and activity of fault, exogenic geological process and hydrogeo- logical conditions-were selected as evaluation indices; Then a hierarchical model was introduced and weight of each factor was determined properly. Quantitative engineering geological evaluation was performed according to Engineer- ing Geological Index and Set Pair Analysis method. Reasonable results was acquired after comparison of preliminary and quantitative evaluation as well as verification of disaster distribution. The referred area was divided into 3 zones and 6 subzones, and a sketch of engineering geological zonation was drawn to serve engineering renovation, disaster prevention and reduction.