川西藏东交通廊道区域工程地质条件评价

Regional engineering geological condition evaluation in the Sichuan-Xizang traffic corridor

区域工程地质条件是重大工程规划建设地质安全的重要保障。川西藏东交通廊道位于青藏高原东部,穿越世界上地形地貌和地质构造最复杂的地区,区域工程地质环境复杂。响应重大工程规划建设的地质安全需求,以川西藏东交通廊道重大线性工程沿线为研究区,在分析区域工程地质环境的基础上,选取9个地质环境因子指标,采用基于GIS的层次分析法,完成了区域工程地质条件评价,将研究区划分为工程地质条件好、较好、中等和差4个等级。结果显示,活动断裂是最不利的工程地质条件因素,其次是地形起伏度和地质灾害易发程度。工程地质条件好的地区远离活动断裂带和深切峡谷,呈块状、条带状分布于活动断裂带及深切峡谷之间。工程地质条件差的地区主要分布于活动断裂带和高山峡谷区,突出表现为距活动断裂较近,尤其是多条断裂相交或近于相交的地区。研究结果能够为川西藏东交通廊道重大工程规划建设地质安全提供科学支撑。

The regional engineering geological conditions are the important guarantee for geological safety of major engineering planning and construction.The Sichuan-Xizang traffic corridor is located in the eastern Qinghai-Xizang Plateau,and passes through the zone with the most complex terrain and geological structure all over the world,and faces the extremly complex regional engineering geological environment.In order to respond to the geological safety requirements of major engineering planning and construction,this paper takes the major linear project regions in the Sichuan-Xizang traffic corridor as the study area.On the basis of summarizing and analyzing the regional geological settings,the regional engineering geological condition evaluation is completed by using the GIS analytical hierarchy process and 9 geological environment factors,and the regional engineering geological conditions are divided into 4levels:good,relatively good,moderate and poor.The results show that the active faults are the most unfavorable factors of engineering geological conditions,followed by terrain relief and geo-hazard susceptibility.The areas with good engineering geological conditions are far away from active faults and deep canyons,and are distributed in the blocks and strips between active faults and deep canyons.The areas with poor engineering geological conditions are mainly distributed in the faut zones and alpine and canyon regions.The outstanding performance is that they are relatively close to strongly active faults,especially the regions with intersection of multiple faults.The research results can provide scientific support for the geological safety of major engineering planning in the Sichuan-Xizang traffic corridor.