中巴公路泥石流灾害破坏及防治优化

Debris Flow Hazards and Prevention Optimization along International Karakoram Highway

中巴公路沿线活跃的地质构造运动、陡峭的地形地貌与冰川气候造成泥石流广泛发育,威胁中巴公路扩建与建成后的运营。分布在中巴公路北段冰川泥石流对该公路的威胁最为严重。根据2008-2011年期间雨季前后泥石流的活动状况,采用沿线普查与重点详查的研究方式,总结中巴公路沿线泥石流灾害的主要危害类型;并结合设计图纸,对2009年以前原中巴公路防治工程进行简要的损毁评估;通过分析中巴公路的防治现状提出相应的防治对策,最终针对典型的病害提出具有代表性的改进措施,以期为高海拔区公路灾害的防治提供一定的参考。研究表明:中巴公路泥石流的危害类型有5种,即淤积、侵蚀、冲击、漫流改道与堵江;损毁评估结果显示原有小型泥石流防治工程基本失效;原大型桥梁工程配套防治工程需要新建或加固;而新建桥梁工程运行良好;泥石流防治工程应考虑以下5个现状:援建工程的性质、不良工程地质条件、公路短期安全与灾害发展趋势的统一、主动工程被动防治及建立灾害管理与公路养护机构;鉴于中巴公路防治工程所面临的"技术经济性"问题,典型防治工程应根据泥石流的分布特征、性质特点与公路的交汇关系,采取因地制宜的防治方案。

The frequent occurrence of debris tlows caused by active tectomc movement, aorupt tc1imn mm complex glacial climate have been threatening the international Karakoram Highway （KKH） on its expan- sion and operation for so many years. The status of debris flow activity before and after the rainy seasons from 2008 to 2011 was comprehensively surveyed by using total survey integrated with detailed point sur- vey method. Five types of debris flow damage were summarized as follows, deposition, abrasive erosion, impact on piers or abutment, unconcentrated flow, and river stoppage. In addition, the damage assessment of prevention project in KKH was executed by using design drawings. The results showed that the original small prevention project was completely failed, and the original large bridge of prevention project required to be rebuilt or reinforced, and the new bridge projects was running well. At last, this study proposed the debris flow control measures in KKH that the prevention project should consider the nature of aided engi- neering, the adverse geological conditions, the unification of road safety and disaster trends, the active projects with passive control, the establishment of disaster management and road maintenance agencies. In view of the technical and economic issues of prevention project in KKH, the prevention programs of typical projects should suite to local conditions, and considering the distribution characteristics of debris flow and its intersection relationship with road construction.