تحليل پايداري و طراحي سيستم نگهداري محل انشعاب تونل هاي پنستاك از تونل آب برسدرودبار لرستان

چكيده انگليسي :

129 Stability Analysis and Support System Design of Bifurcation of Penstock Tunnels with Rudbar Dam Powerhouse Headrace Tunnel Hussein Behzadi Nezhad h behzadinezhad@mi iut ac ir Date of Submission 2011 03 16 Department of Mining Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Lohrasb Faramarzi lfaramarzi@cc iut ac ir Supervisor Masoud Cheraghi cheraghi@cc iut ac ir Abstract Dam and power plant project of Lorestan Rudbar on the aerial parts of Rudbar River and about 100 km south of the town away Aligoodarz in Lorestan province is under construction The water conveyance system consists of the headrace tunnel penstock tunnels and surge shafts Bifurcation resion of Headrace Tunnel of powerhouse to two Penstock tunnels where Bifurcation is that somewhere continuance the fault CHAL HATAM fault intercept the Headrace Tunnel appropriate method for safekeeping and reduce eventual damage caused by fault movement is transforming water through a pipe located in a open tunnel with enough space until accordance with the predicted displacement value from the expected shear stress in the tunnel and not harm the water supply pipes or damage is minimal Thus The long headrace tunnel is bifurcated with the penstock tunnels The main purpose of this research stability analysis and design of temporary support system for the Stabilization of bifurcation area BIF using rock mass engineering classifications of RMR and Q system and 3D numerical modeling Bifurcation area is located in DALAN formation and the rock type of this area consists of limestone dolomitic limestone and gray to dark gray dolomite In this study initially using results of insitu laboratory tests and field perceptions and interpretation of producted results required geomechanical parameters for experimental rock mass classifications RMR Q extracted and Then values RMR 26 33 and Q 0 09 0 5 for bifurcation rock mass is determined In this research the rock mass engineering classifications of RMR and Q system are used to evaluation of support systems of bifurcation area along with the 3D numerical modeling Based on Engineering classification system RMR temporary support system involve Systematic bolts 4 5 m long spaced 1 1 5 m in crown and wall with wire mesh and 100 150 mm conventional shotcrete in crown and 100 mm in sides was proposed Also based on engineering classification system Q temporary support system involve a layer of Steel fibre reinforced sprayed concrete with 250 mm thickness and square rock bolts grid 1 3 m 1 3 m to the approximate length of 6 m was proposed The input data for numerical modeling are evaluated from laboratory and in situ tests interpretation and site investigation Particular attention is given to bifurcation in very weak rock in which large deformations can occur Due to weak rock masses at bifurcation area numerical modeling was performed with using Flac3D software Using the cohesion internal friction angle of bifurcation rock mass stress reduction procedure in Flac3D software and apply the proposed excavation pattern the value of advancing step equal to the 0 8 m was determined According to strength and deformability of rock masses along with the condition of stress ratio K0 the 3D numerical solution for supporting system by FLAC3D software are proposed According to the results of numerical modeling the suitable temporary support systems involve 20 cm thick shotcrete layer along with rock bolts 30 are installed on a 1 m 1 m grid spacing Keywords Stability analysis Headrace tunnel Geomechanical parameters temporary support system

بهزادي نژاد، حسين

تحليل پايداري و طراحي سيستم نگهداري محل انشعاب تونل هاي پنستاك از تونل آب برسدرودبار لرستان

پارامترهاي ژئو مكانيكي , سيستم نگهداري موقت