6929

6471

كارشناسي ارشد

مكانيك سنگ

اصفهان: دانشگاه صنعتي اصفهان، دانشكده معدن

1390

نه، 100ص.‌: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

لهراسب فرامرزي، راحب باقرپور

سعيد مهدوي

14/5/91

عليرضا باغبانان، محمود هاشمي

1396/09/18

كتابنامه

معدن

مهندسي معدن

ID6471

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

105Analysis of Geomechanical Parameters and In Situ Stress of Rock Mass in the Isfahan Shiraz Railway Tunnel Using Back analysis Based on Displacement Monitoring Mahmood Sarikhani Khorami Sarikhani85@yahoo com Date of Submission 2 5 2012 Department of Mining Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Lohrasb Faramarzi Lfaramarzi@cc iut ac irSupervisor Raheb Bagherpour bagherpour@cc iut ac irAbstractThe design of underground structures requires planning and an adequate understanding of the geotechnicalconditions of the area that is being excavated The selection of the engineering form and size ofunderground excavations stability analysis and design of the support system depend on in situ stresses andgeomechanical parameters of the rock mass In recent years the back analysis method has been widelyapplied in geotechnical engineering especially in the underground works The method is based on therequired input physical and mechanical informations and can be divided into displacement back analysismethod stress back analysis method and coupled back analysis method The back analysis applied in thisresearch based on the displacement back analysis method In this research work the mechanical propertiesof the rock mass and the initial stresses were obtained from back analysis of the displacement data Determination of the rock mass strength parameters is very difficult especially in weak rocks Design ofstructures on or in the rock will encounter fewer problems if the rock mass properties are available In situtests and back analysis based on the acquired data from instrumentation can be used to determine thestrength properties of rock mass Back analysis can be very important in this regard and is less expensivethan in situ tests The Isfahan Shiraz railway tunnel No 1 is located in a high stress zone of Sanandaj Sirjan Before excavation the tunnel the geotechnical and geophysical studies has not performed to identify thetype of rocks and water condition of the rock mass The tunnel is in the Shemshak formation belonging tothe Jurassic period and the geologic formations are often contain coal shale and sandstone lenses Due to thelarge deformation the convergence tapes have been installed during and after the excavation In thisresearch for the first time optimized direct back analysis using genetic algorithm was performed forIsfahan Shiraz railway tunnel No 1 by three dimensional finite difference software FLAC3D The elasticmodulus stress ratio cohesion and internal friction angle have been determined by applying a new methodin back analysis In this method displacement was assumed as a function of the unknown parameters Thedifferential of the function was integrated and two equations were obtained These equations were solved byusing genetic algorithm Genetic algorithm showed that this method is a powerful tool to evaluate andoptimize the rock mass geomechanical parameters Moreover the support system of the tunnel has beenanalyzed in this research The support system of the tunnel includes implementation and installation of steelframes wire mesh and shotcrete The ground support interaction method was used to determine the appliedload on the support system Capacity diagrams of the support system were plotted to evaluate the safetyfactor The results showed that the support system doesn t have enough safety Keywords Back Analysis Isfahan Shiraz Railway Tunnel Genetic Algorithm Support Capacity Diagram

لهراسب فرامرزي، راحب باقرپور

سعيد مهدوي

عليرضا باغبانان، محمود هاشمي