scholarly journals Analysis of Squeezing Phenomenon in the Headrace Tunnel of Chameliya Project, Nepal

2014 ◽  
Vol 13 ◽  
pp. 44-51 ◽  
Author(s):  
Pawan Kumar Shrestha ◽  
Krishna Kanta Panthi ◽  
Chhatra Bahadur Basnet
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Cross Section ◽  
Support Pressure ◽  
Rock Mass Properties ◽  
Tunnel Wall ◽  
Hydroelectric Project ◽  
Mass Properties ◽  
Headrace Tunnel ◽  
Tunnel Cross Section

The headrace tunnel of Chameliya Hydroelectric Project, Nepal has faced severe squeezing problems from chainage 3+100m to 3+900m. Due to the severe squeezing and deformation, the tunnel cross section has narrowed considerably along this 800m long tunnel stretch. The tunnel wall closure (deformation) is mostly well over 1 m and the maximum recorded closure exceeds 2m. This paper assesses the squeezing phenomenon along this tunnel stretch through evaluation of rock mass properties and support pressure. Three different methods (two analytical and one 2D finite element numerical modeling program) are used in this analysis. The finding is that it is possible to predict extent of squeezing in tunnel if more than one method is used to verify rock mass mechanical properties. DOI: http://dx.doi.org/10.3126/hn.v13i0.10039HYDRO NEPAL Journal of Water, Energy and EnvironmentIssue No. 13, July 2013Page: 44-51Uploaded date: 3/13/2014

scholarly journals Estimation of Coal and Rock Mechanical Properties for Numerical Modelling of Longwall Extraction

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Tien Dung Le ◽  
Chi Thanh NGUYEN ◽  
Van Chi DAO
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Numerical Modelling ◽  
Deformation Modulus ◽  
Published Data ◽  
Rock Mass Properties ◽  
Mass Properties ◽  
Rock Mechanical Properties ◽  
Simple Numerical Model

Reliable estimation of coal and rock mechanical properties at field scale is a prerequisite for numerical modelling of rock behaviours associated with longwall extraction. This paper describes a systematic approach from data collection, laboratory testing to rock mass properties derivation for simulation of longwall extraction, taking two longwall panels at Quang Ninh coalfield in Vietnam for example. The mechanical properties are verified through comparison with published data of the field, indicating close agreements. A simple numerical model is further developed to demonstrate the proper use of the obtained data. The simulation suggests that the ratio of model length to excavation length should be in the range of 2.5–5; uniaxial compressive strength, deformation modulus and tensile strength can be reduced by a factor of 5.0, 2.13 and 2.0, respectively; and a calibration and validation process must be performed to match in-situ longwall’s behaviours. The approach can be applied for derivation of reliable rock mass properties for numerical simulation of underground excavations.

Modelling of thermal rock mass properties at the potential sites of a Swedish nuclear waste repository

2009 ◽  
Vol 46 (6) ◽  
pp. 1042-1054 ◽  
Author(s):  
Jan Sundberg ◽  
Pär-Erik Back ◽  
Rolf Christiansson ◽  
Harald Hökmark ◽  
Märta Ländell ◽  
...  
Keyword(s):  
Rock Mass ◽  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
Rock Mass Properties ◽  
Mass Properties ◽  
Waste Repository
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