Methodology for tunnel and portal support design in mixed limestone, schist and phyllite conditions: a case study in Turkey

Date

2003-02-01

Author

Koçkar, Mustafa Kerem
Akgün, Haluk

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

152
views

0
downloads

The purpose of this study is to present a methodology for tunnel and support design in mixed limestone, schist and phyllite conditions through investigating two highway tunnel case studies that are located along the Antalya-Alanya Highway in southern Turkey. The main lithologies of the project area are regularly jointed, recrystallized limestone and the weak lithologies of the schist unit (i.e., pelitic schist, calc schist, graphitic phyllite and alternations of these lithologies). A detailed geological and geotechnical study was carried out in the project area, and the tunnel ground support types and categories were determined according to the Q-system, rock mass rating method and New Austrian Tunneling Method (NATM). The shear strength parameters and geomechanical properties of the rock masses were obtained by using the geological strength index (GSI). The deformation moduli and post-failure behavior of the rock masses have been determined. Slope stability analyses were performed at the portal, side or cut slope sections. Kinematic and limit equilibrium analyses incorporating the effects of water pressure were performed for the regularly jointed failed rock slopes. Circular failure analogy was used for the slope stability analyses of irregularly jointed, highly foliated lithologies. Slope support system recommendations were made. A back analysis on a failed slope was performed. The results of the back analysis compared well with the results obtained through the GSI method. The tunnel grounds were divided into sections according to their rock mass classes. The deformations and stress concentrations around each tunnel section were investigated and the interactions of the empirical support systems with the rock masses were analyzed by using the Phase 2 finite element software. The regularly jointed rock masses were modeled to be anisotropic and the irregularly jointed, highly foliated and very deformable soil-like lithologies were modeled to be isotropic in the tunnel finite element analyses.

Subject Keywords

Geotechnical Engineering and Engineering Geology

URI

https://hdl.handle.net/11511/37839

Journal

INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES

DOI

https://doi.org/10.1016/s1365-1609(02)00130-2

Collections

Department of Geological Engineering, Article

Suggestions

OpenMETU
Core

Engineering geological investigations along the Iliksu Tunnels, Alanya, southern turkey Koçkar, Mustafa Kerem; Akgün, Haluk (Elsevier BV, 2003-03-01) The main objective of this study is to assess the engineering geological characteristics of the rock mass and to suggest appropriate support recommendations along the two autoroad tunnel projects, named as Iliksu 1 and lliksu 2, which are located along the Antalya-Alanya Highway. The study area consists of pelitic schist and calc schist overlain by a thick sequence of recrystallized limestone and an intercalation of pelitic schist, calc schist and graphite schist. The tunnel ground support types and categor...
Engineering geological investigations and the preliminary support design for the proposed Ordu Peripheral Highway Tunnel, Ordu, Turkey 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...
Analytical Fragility Curves for Ordinary Highway Bridges in Turkey AVŞAR, ÖZGÜR; Yakut, Ahmet; Caner, Alp (SAGE Publications, 2011-11-01) This study focuses on the development of analytical fragility curves for the ordinary highway bridges constructed after the 1990s. Four major bridge classes were employed based on skew angle, number of columns per bent, and span number (only multispan bridges). Nonlinear response-history analyses (NRHA) were conducted for each bridge sample using a detailed 3-D analytical model subjected to earthquake ground motions of varying seismic intensities. A component-based approach that uses several engineering dem...
Design of anchorage and assessment of the stability of openings in silty, sandy limestone: a case study in Turkey Akgün, Haluk (Elsevier BV, 2004-01-01) This study presents a procedure for the design of anchorage and for the assessment of the stability of openings in silty, sandy limestone through investigating the geotechnical problems of the Hasankeyf historical settlement area in southeastern Turkey, of which a good portion will stay below the reservoir of the proposed Ilisu dam. Rock mass characterization was performed. The RMR and GSI methods were utilized for rock mass classification. The RocLab software was used to determine the shear strength parame...
Displacement monitoring, displacement verification and stability assessment of the critical sections of the Konak tunnel, Izmir, Turkey Yertutanol, Kadir; Akgün, Haluk; Sopaci, Evrim (Elsevier BV, 2020-07-01) The main focus of this study is vertical displacement monitoring and verification along with preliminary support design for the four geotechnical sectors of the twin tube Konak tunnel that was constructed in a highly populated area in Izmir. The displacements of the tunnel that were obtained through numerical analysis were verified by comparing them with the displacements obtained by construction monitoring. In the study area, volcanics, pyroclastics and some sedimentary deposits (sandstone, mudstone and co...

Citation Formats

M. K. Koçkar and H. Akgün, “Methodology for tunnel and portal support design in mixed limestone, schist and phyllite conditions: a case study in Turkey,” INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES, pp. 173–196, 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37839.