عنوان مقاله [English]
Trezaghi defined the first scientific definition for squeezing phenomenon in rocks. According to this definition, squeezing rocks are slowly deformed inside it tunnel by applied stressed without a perceptible change in their volumes. Also, Barla and International Society of Rock Mechanics (ISRM) define squeezing as a result of increasing share stress which cause convergence of tunnel. In this research the squeezing phenomenon of rocks in tunnel are reviewed. In the literatures, different methods including empirical, smi-emperical and theoretical-analytical methods are presented. For example, Singh, Goel, Jethwa and Hoek- Marinos are some of these methods. Imemzadeh Hasham tunnel which is under construction was chosen as a case study and squeezing phenomenon for this tunnel was studied. This tunnel is located in Tehran-Amol connecting road (Haraz road) with 12m width and 9m height. In this project, due to underground water condition, presence of discontinuities and faults in sandstone and shale of different formations, several collapses have been occurred. In this research work, geological conditions, geotechnical properties of rock mass and potential of squeezing and its intensity were studied. Results show that shale of Shemshak formation is in squeezing condition and failure is occurred frequently. Apart from the shale marl with interlayer of limestone and thick limestone of Mobarak formation have also potential of squeezing. As a comparison, it can be said that jethwa method is the best method in studying squeezing phenomenon in rock tunnel excavation.