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        1 - Numerical and Statistical Evaluation of Squeezing Potential of West Kermanshah Tunnel Convey
        Vahed Ghiasi ALI Godarihemat
        In this paper, based on the results of experimental and analytical methods, crushed zone and gurpy rocks masses were identified as the squeezing sections. Then crushed zone and gurpy sections creep parameters at the Bruger model were obtained in the laboratory. Then cru More
        In this paper, based on the results of experimental and analytical methods, crushed zone and gurpy rocks masses were identified as the squeezing sections. Then crushed zone and gurpy sections creep parameters at the Bruger model were obtained in the laboratory. Then crushed zone and gurpy sections modelling using the software Flac2D with burgers model for 30 days (long-term) were performed. Our numerical modelling results show the large displacements due to very low quality of the rock mass and high overburden in this sections of the tunnel. The results of the numerical modelling in the short-term, that TBM shield would be stuck in this section of tunnel. Also modeling this section in the long-term showed that stability and not seen failure of the segmental support system. But effect squeezing in two sections is not critical. Among the important phenomena that makes problem for tunneling, support and tunnel usage is squeezing which is a type of problems that takes place in weak rocks. Squeezing of the rock is time dependent large convergence, which occurs around the tunnel, and is essentially associated with creep caused by exceeding limiting shear strength. Squeezing is one of the important phenomena in the tunneling industry so drilling in the squeezing cases can be causing serious problems. Predicting the amount of displacement, radial strain, shear strain and plastic zone increment as functions of the squeezing degree resonator factors is one of the basic needs in drilling and tunnel maintenance. Squeezing is behavior that related with weak rock mass deformation and strength properties. This phenomenon is associated with large deformations and time dependent convergence during tunnel excavation. It takes place when a particular combination of induced stresses and material properties pushes some zones around the tunnel beyond the limiting shear stress at which creep starts. Deformation may terminate during construction or continue over a long period of time. West Kermanshah tunnel conveyance (WKTC), with about 8550 meters long and 6.884 m in diameter in the west of Iran is located in Kermanshah province. Mainly parts of the tunnel pass through weak rock make is including types of argillaceous, sandstone and shale, with high 570 meters overburden and will be probably under squeezing condition. Duets in this project the effect of experimental methods, analytical and semi-analytical are evaluated. Then critical section of the squeezing potential presented and finally numerical modelling of this phenomenon is done. Manuscript profile
      • Open Access Article

        2 - Numerical modeling of segmental lining of Golab water conveyance tunnel due to reduced environmental impact
        mehdi saneiaraei meisam hakimianbidgoli mohamadamin vashadi araei
        Lack of proper drinking water is a major problem in the Central and Eastern cities of the country. Therefore, the necessity of water transmission projects are posed and since meeting these needs using traditional methods are very difficult, time-consuming and costly; so More
        Lack of proper drinking water is a major problem in the Central and Eastern cities of the country. Therefore, the necessity of water transmission projects are posed and since meeting these needs using traditional methods are very difficult, time-consuming and costly; so the mechanized excavation of tunnels and segmental lining are used. The water transferred through the pipes has significant surface destruction. That would result in serious environmental problems. Also, transferring water through the pipes is more expensive than the tunnel. In this paper, after introducing all procedures of segments design, segmental lining of Golab water conveyance tunnel using finite element was modeled.  Firstly, loads on  segmental lining was determined by UDEC software after installation in tunnel. Then, these amounts of load on the segments used for modeling was applied in ABAQUS software. Results obtained by 3D modeling software showed that the greatest amount of displacement of segments under different stress conditions concerns to the bottom segment. Based on the performed modeling, due to the high compressive stress, the crack is only seen in segment concrete and these results are totally in compliance with Golab tunnel segments observations.   Manuscript profile