Representing a modern method to tunnel stability analysis with introducing a new scheme for Ground Reaction Curve (GRC); case study: Garin dam water Diversion tunnel

Subject Areas :

S.M Hoseini ¹ , کاوه Ahangari ² , کامران Goshtasbi ³

1 - کارشناسی ارشد مهندسی استخراج معدن، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران
2 - عضو هیئت علمی گروه معدن دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران
3 - عضو هیئت علمی گروه مهندسی معدن، دانشگاه تربیت مدرس، تهران

Received: 2016-09-06 Accepted : 2016-09-06 Published : 2010-06-22

Keywords: Garin Dam, Diversion Tunnel, Numerical Analysis, GRC and SCC Charts, Phase2, 7.0 and FLAC 4.00 Software,

Abstract :

The most important problem in tunneling project about design and performance is selectionsuitable pattern for drilling and support system, in order to stability of rock mass and reductionplasticity zone. Meanwhile determine the amount of tunnel wall deformation prior to supportinstallation is of great importance. When a tunnel is excavated, there is a certain amount ofdeformation, usually 35-45 percent of the fnal tunnel wall deformation, before the support canbe installed. Determining this deformation can be done using either a) observed feld values, orb) numerically from 3D fnite-element models or symmetrical fnite-element models, or c) byuse of empirical relationships such as those proposed by Panet or Vlachopoulos-Diederichs. Inthis paper, convergence-confnement method is applied to tracing ground characteristic curveusing numerical software models and then stress relaxation is exerted to modal that equivalentwith occurred critical convergence until prior to support installation. In this study, a new chartis introduced which unlike conventional charts, the modulus reduction flow has been used inthat vertical axis. Finally the safety factor of support system has been calculated by three different methods.