Abstract
Determining in-situ soil or rock geotechnical properties is a difficult task for a design engineer. Back analysis is a helpful technique for evaluating soil property by considering and measuring the convergence of an underground opening. Back analysis was performed by matching numerical modeling results with the measured tunnel convergence. The main purpose of this study was to determine optimum rock mass properties using back analysis in order to suggest the best and most economical support system. Accordingly, the difference between measured and calculated convergence values was minimized by using an error function (objective function). In this paper, through the parameters obtained from back analysis, a support system based on a set consisting of shotcrete, wire mesh, and lattice girder was suggested for the Babolak water conveyance tunnel in Mazandaran, Iran. Therefore, the suggested design was based on decreasing shotcrete thickness from 25 to 20 cm and eliminating of rock bolts.
Similar content being viewed by others
References
Bagherzadeh A (2008) Stability analysis of Esfahan subway twin tunnels at the location of tunnels conversion to one tunnel by using numerical modeling. Department of Mine and Metallurgy, Sahand University, Tabriz
Bonadaki DM (2001) Convergence and it control in tunnels. Shahroud University Publications, Shahroud, pp 70–90
Cai M, Morioka H, Kaiser PK, Tasaka Y, Kurose H, Minami M, Maejima T (2007) Back-analysis of rock mass strength parameters using AE monitoring data. Int J Rock Mech Min Sci 44:538–549
Carranza-Torres C, Fairhurst C (1999) The Elasto-plastic response of underground excavations in rock masses that satisfy the Hoek-Brown failure criterion. Int J Rock Mech Min Sci 36:777–809
Cividini A, Jurina L, Gioda G (1981) Some aspects of characterization problems in geomechanics. Int J Rock Mech Min Sci 18:487–503
Cividini A, Maier G, Nappi A (1983) Parameter estimation of a static geotechnical model using Bayes approach. Int J Rock Mech Min Sci 20:215–226
Fahimifar A (1998) Underground structures in rock. Technical and Soil Mechanic Laboratory of Road and Transport Ministry Publications, Tehran, pp 70–120
Gioda G (1985) Some remarks on back analysis and characterization problem in geomechanics, 5th International conference on numerical methods in geomechanics. Nagaya, Japan, 47–61
Gioda G, Maier G (1980) Direct search solution of an inverse problem in elastoplasticity: identification of cohesion, friction angle and in-situ stress by pressure tunnel tests. Int J Numer Methods Eng 15:1832–1848
Hoek E, Kaiser PK, Bawden WF (1995) Support of underground excavation in hard rock. A. A. Balkema, Rotterdam
Iding RH, Pister KS, Taylor RL (1974) Identification of non-linear elastic solids by a finite element method. Comput Methods Appl Mech Eng 4:121–142
Itasca Consulting Group, Inc. FLAC 2D, Fast Lagrangian Analysis of Continua, version 5, user's manual
Jeon YS, Yang HS (2004) Development of back analysis algorithm using FLAC. Int J Rock Mech Rock Eng 41(3):22–29
Kavanagh KI, Clough RW (1971) Finite element application in the characterization of elastic solid. Int J Solids Struct 7:11–23
Ladesma A, Gens A, Alonso EE (1991) Identification of parameters of non-linear geotechnical models, in computer methods and advances in geomechanics. Balkema, Rotterdam, pp 1005–1010
Mahab Ghods Consulting Engineering Company (2009) Report of introduction, implemented studies and execution characteristics of Babolak water conveyance tunnel. Tehran, Iran, 1–13
Murakami A, Hasegawa T (1987) Back analysis by Kalman filter-finite elements and optimal location of observed points. Proc 22nd Japan National Conf on Soil Mechanics and Foundation Engng 2:1033–1036
Oreste P (2005) Back-analysis techniques for the improvement of the understanding of rock in underground constructions. Tunnelling and Underground Space Technology 20:7–21
Sakurai S (1997a) Lessons learned from field measurements in tunneling. Tunnelling and Underground Space Technology 12(4):453–460
Sakurai S (1997) Monitoring and performance in tunneling. Proceeding of the Fourteen International Conference on Soil Mechanics and Foundation Engineering. Hamburg, Germany, 2409–2412
Sakurai S, Takeuchi K (1983) Back analysis of measured displacements of tunnels. Rock Mech Rock Eng 16:173–180
Swoboda G, Ichikawa Y, Dong Q, Zaki M (1999) Back analysis of large geotechnical models. Int J Numer Anal Meth Geomech 23:1455–1472
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Dadashi, E., Ahangari, K., Noorzad, A. et al. Support system suggestion based on back-analysis results case study: Babolak water conveyance tunnel. Arab J Geosci 5, 1297–1306 (2012). https://doi.org/10.1007/s12517-011-0288-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12517-011-0288-5