复杂艰险山区地质灾害特征及减灾选线研究

Research on Geological Disaster Characteristics and Location for Disaster Reduction in Complex and Dangerous Mountainous Areas

随着西部铁路路网规划及建设的加速,地质灾害已成为铁路建设、运营中不可绕避及忽视的工程地质问题;复杂艰险山区受内外动力地质作用强烈,具有大高差地形地势、复杂活跃的构造运动、破碎的地层岩性及高地应力等特征,其地质灾害类型多、分布广。本文针对复杂艰险山区地质灾害类型,在分析其特征的基础上,探讨了地质灾害对铁路的影响,进而研究减灾选线的原则,以期为工程建设服务。主要结论有:(1)复杂艰险山区主要发育有崩滑泥石流等重力不良地质、岩溶涌水突泥、地震震裂及次生灾害、沟谷型灾害链、高地应力、高温热水、有害气体、活动断裂等地质灾害;(2)地质灾害受内外动力地质作用耦合的影响,具有复杂性、隐蔽性、随机性等特点,难以完全查明;(3)因高速度目标值及高舒适性的需求,铁路工程选线在深度的剖面上及广度的平面上难以完全绕避,地质灾害对铁路工程建设和运营安全有较大影响;(4)铁路工程选线应树立减灾选线的理念,重视地质灾害的早期识别和风险规避与防控,从源头上规避和减轻地质灾害对铁路的影响。

With the acceleration of the planning and construction of the western railway network,geological disasters have become engineering geological problems that cannot be avoided and ignored in railway construction and operation.Complex and dangerous mountain areas are strongly affected by internal and external dynamic geological actions,with the characteristics of large elevation difference topography,complex and active tectonic movements,broken strata lithology and high ground stress.There are many types of geological disasters widely distributed in areas.According to the types of geological disasters in complex and dangerous mountainous areas,based on the analysis of their characteristics,the influence of geological disasters on railways is discussed,and then the principles of location for disaster reduction are researched for the construction in the paper.The main conclusions are as follows:(1)There are mainly geological disasters such as unfavorable gravity geology(landslide and debris flow),karst water and mud gushing,earthquake cracking and secondary disasters,valley-type disaster chain,high ground stress,high-temperature-hot-water,harmful gases and active faults.(2)Geological disasters are affected by the coupling of internal and external dynamic geological actions and are characterized by complexity,concealment and randomness,so they are difficult to be completely identified.(3)Due to the high-speed target value and high comfort demand,it is difficult to completely avoid the disasters for the railway location in the depth profile and the breadth plane,so geological disasters have a great impact on the railway project construction and operation safety.(4)For the railway location,the concept of location for disaster reduction shall be established,the early identification of geological disasters and risk avoidance and prevention&control shall be considered,and the impact of geological disasters on the railway shall be avoided and mitigated from the source.