The first and fundamental phase of the tunnel project is ground modeling which, starts with a desk study on local geology and continues with detailed ground investigation activities. Ground investigation works are of great importance as it is the main factor that determines investment and operating cost, tunnel alignment, the tunnel cross- section, and construction method. The parameters determined during the investigations are divided into three groups: geological, hydrogeological,geomorphological. During the ground investigation, gathering accurate geological data play a significant role in cost determination, risk control, and project design. However, current GI activities are not able to define the 100% correct geological model due to its constraints and complexity of ground.