The uncertainty in the measurement of rock mass is largely due to the inherently heterogeneous nature of the rock mass itself. A variety of environmental conditions influence the engineering behaviour of the rock mass. Antalya settlement area is located on the travertine deposits. Travertines were affected by domestic and industrial liquid waste, which was injected directly into the travertine plateau through septic holes in Antalya prior to 2000. This situation resulted in poor engineering properties in travertine rocks, such as high deformation and low strength. It can cause issues in travertine foundation excavations. Determining all engineering parameters, ordering their weights and clarifying their uncertainty effects are especially difficult tasks in tunnel excavations. This paper addresses the most important aspects of the Antalya 3rd Stage Rail System tunnel project and examines the rock mass properties of karstic travertines.