西秦岭北缘断裂带西端的活动性及其对西宁至成都铁路方案的影响  

The Activity of the West End of the Western Qinling Fault Zone and Its Influence on the Railway Project from Xining to Chengdu

作　　者：张志亮[1] ZHANG Zhiliang(China Railway First Survey and Design Institute Group Co.,Ltd.Xian,710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《华南地震》2020年第2期85-91,共7页South China Journal of Seismology

基　　金：铁一院科研项目(院科17-12)资助。

摘　　要：西秦岭北缘断裂带是青藏高原东北缘一条强烈活动的Ⅱ级块体边界断裂,曾发生过多次6.5级以上大震。规划中的西宁至成都铁路设计线路拟从甘家盆地一带穿行,西秦岭北缘断裂带西段的活动性及其端部终止位置,直接关系到铁路安全。基于甘家盆地一带的第四纪地质地貌与断裂活动性调查结果,对西秦岭北缘断裂带的西端活动性及其对铁路方案的影响进行了分析和讨论。结果显示:西秦岭北缘断裂带西段发散为两条主要活动断层,均有全新世地表弱活动迹象;断裂西端终止于甘家盆地东缘一带,铁路设计方案在甘家盆地一带未直接穿经西秦岭北缘断裂带,未来遭遇突发位错的可能性不大,但需要考虑该断裂可能产生的地震动影响。The western Qinling fault zone,one of boundary faults of one secondary active block located on the northeastern margin of the Tibet Plateau,actives strongly and occurred several earthquakes with M≥6.5 in history.The planned railway project from Xining to Chengdu run through Ganjia basin adjacent to the western Qinling fault zone,so the decision of the activity and west end of the fault zone have close relations to the planed railway project.Based on the field investigation on the Quaternary geology,geomorphology and faults activity around the Ganjia basin,this paper analyzed and discussed the activity of the west end of the fault zone and its influence on the railway project.The results suggest that the western segment of the western Qinling fault zone is divided into two branch active faults,and both of which show signs of weak Holocene surface activity.However,the west end of the fault zone terminates at the eastern margin of the Ganjia basin,and the planed railway lines does not traverse the fault zone directly in the area around the Ganjia basin.Therefore,for the railway project,it is less likely to encounter sudden offsets aroused by the western Qinling fault zone,and the seismic ground motion is the main effect to consider.

关 键 词：西秦岭北缘断裂 活动断裂 甘家盆地 西成铁路 

分 类 号：U212.32[交通运输工程—道路与铁道工程]