川藏交通廊道沿线板块缝合带地质灾害效应

板块缝合带作为特殊类型的“断层”,其地质灾害效应是工程地质与灾害地质研究的重要内容,对工程建设具有重大现实意义.受特提斯洋复杂而漫长的构造演化制约,川藏交通廊道穿越了7条板块缝合带,但对其地质灾害效应的研究却鲜有涉及.为此,在搜集整理已有研究成果的基础上,结合野外地质调查和室内研究,简要分析了川藏交通廊道沿线板块缝合带的地质灾害效应,并探讨其内在机理.结果表明:板块缝合带地质灾害效应主要表现在塑造地貌、创造地形条件,劣化岩体、提供物质来源,控制地质灾害的分布和诱发地质灾害（链）等4方面.构造混杂岩因其复杂的地质演化过程和特殊的岩石类型与组合特征,使其天然具有易灾性,而板块缝合带就位过程中的构造运动是地质灾害效应的内生动力.板块缝合带的地质灾害效是贯穿于川藏交通廊道沿线板块缝合带构造演化过程中的内、外动力地质作用耦合的外在表现形式.板块缝合带地质灾害效应研究目前处于起步阶段,建议在加强基础地质与灾害地质精细化调查的基础上深化其认识;川藏交通建设工程应加强板块缝合带工程效应研究,加大地质灾害监测预警系统研发,以确保其安全施工与后期平稳运行. 

Geohazard Effect of Plate Suture Zone along Sichuan-Tibet Traffic Corridor

Plate suture zone, a special type of "fault", its geohazard effect is an indispensable content in the study of engineering geology and hazard geology, and has great practical significance for engineering construction. Constrained by the complex and long tectonic evolution of the Tethys Ocean, there are 7 plate suture zones along the Sichuan-Tibet traffic corridor, but the study on their geohazard effect is rarely involved. Based on collecting and sorting out the existing research results, combined with field geological survey and laboratory research, in this paper it briefly analyzes the geohazard effect of plate suture zone along the Sichuan-Tibet traffic corridor, and discusses its internal mechanism. The results show that the geohazard effect of plate suture zone is mainly reflected in four aspects, namely shaping landform, creating topographic conditions, degrading rock mass, providing material sources, controlling the distribution and inducing geohazards (chain). Tectonic mélange is of natural disaster prone because of its complicated geological evolution process and special lithologic type and assemblage characteristics, and the tectonic movement during the emplacement of plate suture zone is the endogenous driving force of geohazard effect. The geohazard effect of the plate suture zone is the external manifestation of the coupling of internal and external dynamic geological processes during the tectonic evolution of the plate suture zone along the Sichuan-Tibet traffic corridor. The study on the geohazard effect of plate suture zone is at the initial stage, and it is suggested to deepen the understanding on the basis of detailed investigation of both basic geology and hazardous geology. For the construction of Sichuan-Tibetan traffic corridor, it is quite necessary to strengthen the research on engineering effect of plate suture zone and the research and development of geohazard monitoring and early warning system to ensure its safe construction and smooth operation.