Program Assumptions

There are some important limitations and assumptions of the RocTunnel3 program that should be considered when interpreting the results:

• Block Failure should be analyzed along excavation surfaces cut in hard rock where discontinuities are discrete (finite) and perfectly planar.
• Displacements take place along the Joints and Blocks move as rigid bodies with no internal deformation or cracking.
  
• Blocks can be formed by any number of Joint Intersections (e.g., one Joint is planar, two Joints is wedge, etc.).
• The Location, Orientation, and extents of Joints dictate possible Joint Intersections and formation of Blocks (i.e., non-ubiquitous Joints). How and if Joints intersect will determine if a Block can form, its Geometry (which has an impact on Removability) and dimensions (i.e., volume).
• Rock mass strength and rock bridging is not considered where Joints do not sufficiently persist to form closed volumes.
• Without the consideration of external Loads and Supports, only gravitational loading due to self-weight is modeled as the driving force in limit equilibrium analysis to compute the Factor of Safety.
• Without the consideration of external Loads and Supports, only Shear Strength along sliding Joints is modeled as the resisting force in limit equilibrium analysis to compute the Factor of Safety