Abstract
For quantitative identification of rock behavior in shallow tunnels, we recommend using the rock behavior index (RBI) within the Rock Engineering Systems (RES) approach. RES can aid engineers in effectively determining complex and un-structured rock behavior utilizing interaction matrices. Rock behavior types can be classified into three groups: cave-in, rock fall and plastic deformation. Seven parameters influence rock behavior: rock mass compressive strength, rock quality designation (RQD), joint surface condition, stress, ground water, earthquake, and tunnel span. An advantage of RES is its ability to obtain each parameter's weighting. We quantified the rock behavior into RBI on fall, cave-in, and plastic deformation. The study results demonstrate that RES can give engineers quantitative information on rock behavior. The proposed model is illustrated via a case study on Seoul Metro Line 9.