麻城—团风断裂的空间展布及对拟建沪渝蓉高铁合武段的工程影响

Spatial distribution of Macheng-Tuanfeng fault and its influence on the Hefei-Wuhan section of the proposed Shanghai- Chongqing-Chengdu high-speed railway

摘要:

拟建沪渝蓉高铁合肥至武汉段线路和麻城—团风断裂带于鄂东北内麻城市黄土咀附近相交。在综合分析既往研究材料的基础上,通过开展野外地质调查、浅层地震勘探和地质钻探等工作,查明了麻城—团风断裂与拟建线路相交处准确的空间展布和断裂性质,综合分析判断断裂的活动性及其可能对拟建线路工程造成的影响。研究表明:麻城—团风断裂与拟建线路相交位置仍属于该断裂北段,具东、西2条分支,由3条隐伏断裂组成;其中,阎家河两岸2条NNE向逆冲断裂为麻团断裂北段西支,是断裂的主体部分,而东侧1条NE向断裂为麻团断裂带北段东支且年代较老的断裂;研究区麻团断裂为中更新世中晚期断裂,活动性较弱,但该断裂具备发生6级左右地震的构造背景和地震构造条件,拟建线路穿过该断裂时,需要采取相应的抗震和预警措施。该研究为后续线路工程设计及施工提供了相应的工程措施建议。

Abstract:

The Hefei-Wuhan section of the proposed Shanghai-Chongqing-Chengdu high-speed railway intersects with the Macheng-Tuanfeng fault near Huangtuzui, Macheng City in northeastern Hubei. Comprehensive analysis of previous materials was used as the basis, and through field geological survey, shallow seismic exploration, and geological drilling, the accurate spatial distributions and fault properties of the intersection of the Macheng-Tuanfeng fault and the proposed line were identified. Moreover, fault activity and its possible impact on the proposed line were comprehensively analyzed. According to research results, the intersection of the Macheng-Tuanfeng fault and the proposed line still belongs to the north section of the Macheng-Tuanfeng fault, which has two branches in the east and west and is composed of three hidden faults. The NNE-trending thrust faults on both banks of Yanjiahe River are the west branch of the north segment of the Macheng-Tuanfeng fault, which is the main part of the fault, and one NE-trending fault on the east side is the east branch of the north segment of Macheng-Tuanfeng fault. The Macheng-Tuanfeng fault in the study area is a fault in the mid-late Pleistocene with weak activity. However, the fault has tectonic background and seismotectonic conditions for earthquakes with a magnitude of approximately 6. When the proposed line crosses this fault, earthquake-resistant and early warning measures need to be considered. This study provides engineering measures and suggestions for the engineering design and construction of subsequent lines.