工程地质岩组与岩体质量分级在岩石工程中应用对比

APPLICATION COMPARISON OF ENGINEERING GEOLOGICAL ROCK GROUP AND ROCK MASS CLASSIFICATION IN ROCK ENGINEERING

在多不良地质体存在条件下,不同建设阶段岩体质量级别判别结果常会出现较大差别,成为岩石工程建设中争论焦点之一。岩体质量分级可给出相应力学参数,但对复杂地质体的变形破坏模式难以区分,影响到合理的开挖和支护方案的制定。结合岩石工程目标,在地层岩性对比和相应物理力学特性区分基础上,划分出的工程地质岩组,成为了工程地质条件评价、分区和工程规划的重要基础。在岩石地下工程设计和施工中还需有岩体质量分级作为依据。前者是以岩体工程地质力学观点为基础的较大范围的定性分类,抓住地质体关键内因之一的岩体地质建造和构造改造来分类,有利于得出相应变形破坏模式;后者以单指标或多指标来计算评判岩体质量好坏,包括了工程岩体本身和所处地质环境因素。在岩石工程不同阶段和不同层次上,它们的依据和应用各有所长,对工程地质问题的大尺度超前预报和工程设计起着不同作用,而又有一定的交叉和重叠,结合起来运用可发挥合理解释变形破坏模式和对比不同阶段判别结果的工程效果。结合雁门关隧道工程,给出它们的应用情况对比,以便于其在不同工程建设中更好地区别运用。

Due to existence of various unfavorable geological bodies,assessment results of rock mass quality are often varied at different stages of construction,and induce some arguments. In order to assist in rock engineering aims,the engineering geological rock grouping is necessary to carry out on analyses of lithology and physi-mechanical features,for differentiation of main components of engineering geological zonation and evaluation. The widely applied rock mass quality classification is useful in rock engineering design and construction for surrounding rock stability purpose. The former comes from the viewpoint of rock mass structural control and takes account of rock mass types from a large range,while the latter adopting single or multiple parameters for assessment rock mass quality,including rock mass itself and surrounding environment. At different stages and layers,the two methods play distinctive roles,as for large scale geological forecast and engineering design, respectively,but with somewhat joints and overlays. The obvious differences of rock mass quality indices obtained at various stages of construction,can be clarified and interpreted from views of engineering geological rock group,with respect to unfavorable geological bodies. Taking the Yanmenguan Tunnel as one case example,their roles and application process are presented and discussed. The different advantages of the two systems and obtained results could be used in other rock engineering projects.