Support capacity estimation of a diversion tunnel in weak rock

Ozsan, A
Basarir, H
This paper presents the results of the support capacity estimation for the diversion tunnel of the Urus dam site in highly weathered tuff and weak zone. Tunneling in weak rock requires some special considerations, since misjudgment in support design results in costly failures. There are several ways of estimating rock support pressure and selecting support. However, all systems suffer from their characteristic limitations in achieving objectives. Thus, it is more useful to use different methods for estimating support pressure and type of support. The support pressure pi was established by three different methods. These methods are the (1) empirical methods based on rock mass rating (RMR) and rock mass quality index (Q-classification systems), (2) ground support interaction analysis (GSIA) and (3) numerical methods, namely, Phase 2 finite element (FEM) program. Rock masses were characterized in terms of RSR, RMR, Q-system and GSI. Drill-core samples were tested in the rock mechanics laboratory to determine physico-mechanical properties. Rock mass strength was estimated by empirical methods. Finally, the required support system is proposed and evaluated by different methods in the highly weathered tuff and weak zone of the diversion tunnel.


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Ozsan, A; Karpuz, Celal (Elsevier BV, 1996-03-01)
This paper describes a feasibility-level geotechnical evaluation carried out at Anamur dam site, in terms of stability analysis of dam foundation, excavation slopes and a diversion tunnel. The proposed Anamur dam will be built across the Anamur river on the Alanya metamorphic series which consists of phyllite, schist and slate units at the site. Geotechnical investigations included drilling for core, pumping tests, sampling for laboratory testing, and a detailed discontinuity survey.
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Sopaci, Evrim; Akgün, Haluk (Elsevier BV, 2008-01-07)
This paper presents engineering geological investigations and the tunnel support design for the Boztepe tunnel of the Ordu Peripheral Highway located in northeast Turkey. In order to characterize the rock masses in Boztepe Tunnel which mainly consist of flysch (mostly alternation of sandstone, marl and siltstone) and pyroclastics (agglomerate and tuff), engineering geological investigations have been carried out in three stages as surface, subsurface and laboratory investigations. Rock mass classification s...
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ÇABALAR, ALİ FIRAT; Dulundu, Kemal; Tuncay, Kağan (Elsevier BV, 2013-04-01)
This paper presents the result of an extensive series of experimental investigation carried out in triaxial and cyclic direct shear tests on sands having various properties, which were obtained from different locations in Turkey and in Northern Cyprus. In order to investigate the link between strength and physical properties (i.e., shape) of the sand particles, three series of triaxial tests (Consolidated-Drained, CD; Consolidated-Undrained, CU; and Unconsolidated-Undrained, UU) for each were performed unde...
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Citation Formats
A. Ozsan and H. Basarir, “Support capacity estimation of a diversion tunnel in weak rock,” ENGINEERING GEOLOGY, pp. 319–331, 2003, Accessed: 00, 2020. [Online]. Available: