scholarly journals Predicting Tunnel Squeezing: A Discussion based on Two Tunnel Projects

2013 ◽  
Vol 12 ◽  
pp. 20-25 ◽  
Author(s):  
Krishna Kanta Panthi
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Uncertainty Analysis ◽  
Fault Zones ◽  
Tectonic Fault ◽  
Rock Support ◽  
Reliable Prediction ◽  
Rock Mass Strength ◽  
Tunnel Convergence ◽  
The Himalaya

Tunnel squeezing is a phenomenon, which is frequently confronted while tunneling through Himalayan rock mass. Weak and schistose rocks like mudstone, shale, slate, phyllite, schist, highly schistose mica gneiss and the rock mass of the tectonic fault zones are incapable of sustaining high stresses. A reliable and trustworthy prediction on the extent of squeezing is therefore essential. The reliable prediction results help to make strategy regarding stabilizing measures and optimization of tunnel rock support well in advance. This paper is mainly focused in analyzing the tunnel squeezing that took place in connection with the two tunnel cases; i.e. Kali Gandaki 'A' and Middle Marsyangdi headrace tunnels. The main focus is given to look on the applicability of squeezing analysis using Hoek and Marinos approach in combination with the equation proposed by Panthi for the estimation of rock mass strength for highly schistose rocks of the Himalaya. The measured tunnel convergence (squeezing) and lab tested mechanical properties of the rocks from these two headrace tunnels have been used to verify the applicability of the proposed methods and also the uncertainty analysis approach on squeezing introduced by Panthi.Hydro Nepal; Journal of Water, Energy and EnvironmentVol. 12, 2013, JanuaryPage: 20-25DOI: http://dx.doi.org/10.3126/hn.v12i0.9027Uploaded Date : 10/28/2013

scholarly journals Implementation of probabilistic approach to rock mass strength estimation while excavating through fault zones

2019 ◽  
Vol 13 (4) ◽  
pp. 72-83 ◽  
Author(s):  
D Babets ◽  
O Sdvyzhkova ◽  
O Shashenko ◽  
K Kravchenko ◽  
E. C. Cabana
Keyword(s):  
Rock Mass ◽  
Probabilistic Approach ◽  
Fault Zones ◽  
Rock Mass Strength

ROCK MASS STRENGTH IN RELATION TO LANDSLIDE PROGRESSION

2018 ◽  
Author(s):  
Brooke M. Hornney ◽  
◽  
Marlene C. Villeneuve ◽  
Jonathan Davidson
Keyword(s):  
Rock Mass ◽  
Rock Mass Strength

scholarly journals Determination of Mechanical Properties of Altered Dacite by Laboratory Methods

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 813
Author(s):  
Veljko Rupar ◽  
Vladimir Čebašek ◽  
Vladimir Milisavljević ◽  
Dejan Stevanović ◽  
Nikola Živanović
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rock Mass ◽  
Uniaxial Compressive Strength ◽  
Rock Material ◽  
Strength Parameter ◽  
Gradual Transition ◽  
Strength Parameters ◽  
Triaxial Compressive Strength ◽  
Heterogeneous Rock

This paper presents a methodology for determining the uniaxial and triaxial compressive strength of heterogeneous material composed of dacite (D) and altered dacite (AD). A zone of gradual transition from altered dacite to dacite was observed in the rock mass. The mechanical properties of the rock material in that zone were determined by laboratory tests of composite samples that consisted of rock material discs. However, the functional dependence on the strength parameter alteration of the rock material (UCS, intact UCS of the rock material, and mi) with an increase in the participation of “weaker” rock material was determined based on the test results of uniaxial and triaxial compressive strength. The participation of altered dacite directly affects the mode and mechanism of failure during testing. Uniaxial compressive strength (σciUCS) and intact uniaxial compressive strength (σciTX) decrease exponentially with increased AD volumetric participation. The critical ratio at which the uniaxial compressive strength of the composite sample equals the strength of the uniform AD sample was at a percentage of 30% AD. Comparison of the obtained exponential equation with practical suggestions shows a good correspondence. The suggested methodology for determining heterogeneous rock mass strength parameters allows us to determine the influence of rock material heterogeneity on the values σciUCS, σciTX, and constant mi. Obtained σciTX and constant mi dependences define more reliable rock material strength parameter values, which can be used, along with rock mass classification systems, as a basis for assessing rock mass parameters. Therefore, it is possible to predict the strength parameters of the heterogeneous rock mass at the transition of hard (D) and weak rock (AD) based on all calculated strength parameters for different participation of AD.

Rock Mass Strength Assessment for Bedrock Landsliding

1996 ◽  
Vol II (3) ◽  
pp. 325-338 ◽  
Author(s):  
K. M. SCHMIDT ◽  
D. R. MONTGOMERY
Keyword(s):  
Rock Mass ◽  
Strength Assessment ◽  
Rock Mass Strength
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