Three-Dimensional Analysis of Permanent Covering Behavior of Gelevard Dam Injection Gallery and Optimal Design of Tunnel Coverage
Abstract: Gelevard dam is one of the under construction dams in Iran. Gallery tunnels have been executed to implement the possibility of appropriate grout curtain, complete sealing of support and dam foundation. Current paper has studied and analyzed the left bottom gallery (LG3) with length of 380 meters, 3 meters drilling diameter and optimal coverage concrete thickness of gallery. The required armature in the appropriate host rock pile has been determined average and weak. Accordingly, the optimal thickness of gallery covering concrete has been assumed 30 centimeters in the roof and walls, 45 centimeters on the floor. Geometry of this area has been modeled commensurate with the reality in the software limited elements as much as possible. Results have been presented in graphs, after evaluation of place changes, minimum and maximum tensions, axial force, shear force and bending moment. The obtained results indicated that30 centimeters thickness permanent concrete coverage without armature and 1.5 meters and 3 meters thickness of grout area of weak host rock is suitable for the host rock with appropriate quality and average one. The 40 centimeter thickness armature concrete coverage and injection thickness of 4.5 meters can be appropriate as well.