Rock mass characterization for an underground excavation support system: the sabzkuh water conveyance tunnel, Iran

2004 ◽  
Vol 41 (3) ◽  
pp. 532-533 ◽  
Author(s):  
M. Hashemi ◽  
R. Ajalloeian ◽  
Sh. Moghaddas
Keyword(s):  
Rock Mass ◽  
Support System ◽  
Underground Excavation ◽  
Rock Mass Characterization ◽  
Water Conveyance ◽  
Excavation Support ◽  
Water Conveyance Tunnel

Support system suggestion based on back-analysis results case study: Babolak water conveyance tunnel

2011 ◽  
Vol 5 (6) ◽  
pp. 1297-1306 ◽  
Author(s):  
Ehsan Dadashi ◽  
Kaveh Ahangari ◽  
Ali Noorzad ◽  
Alireza Arab
Keyword(s):  
Support System ◽  
Back Analysis ◽  
Water Conveyance ◽  
Water Conveyance Tunnel

scholarly journals Estimating TBM Specific Energy by Employing the Rock Mass Strain Energy, A Case Study: Karaj – Tehran Water Conveyance Tunnel located in Iran

2021 ◽  
Author(s):  
Majid Mirahmadi
Keyword(s):  
Rock Mass ◽  
Specific Energy ◽  
Strain Energy ◽  
Strain Curve ◽  
Rock Mass Classification ◽  
Geological Strength Index ◽  
Peak Strain ◽  
Water Conveyance ◽  
Mass Classification ◽  
Water Conveyance Tunnel

Abstract Recently energy costs are increasing so it is critical to master the challenge of energy efficiency. Energy consumption for drilling in tunnel Boring Machines (TBMs) is mainly determined by the specific energy. Specific energy is the amount of energy needed to excavate a unit volume of rock mass and is considered one of the important parameters used for performance prediction of TBMs. This study tries to apply the strain energy of a rock mass to develop a new method for foretelling specific energy for TBM. The area under complete stress–strain curve is known as strain energy which is pertinent to the rock mass behavior, pre and post failure properties, peak strain and post peak strain. In this study statistical analysis performed through collected actual data from Karaj Tehran Water Conveyance Tunnel revealed a new relationship between the specific energy used by TBM (SE) and the strain energy. For more detailed study the rock mass classification is performed with respect to the geological strength index and all geological units are then classified in three classes and the specific energy of TBM is predicted based on the strain energy of rock mass for each three classes. The results reveals that two parameters of the specific energy and the strain energy are in a direct relation whose correlation is increased with considering the rock mass classification based on the post peak behavior of rock mass.

Influence exerted by underground excavation shape and by effective stresses on the formation of a tensile strain zone at a depth greater than 1 km

2020 ◽  
pp. 67-75
Author(s):  
Van Min Nguyen ◽  
V. A. Eremenko ◽  
M. A. Sukhorukova ◽  
S. S. Shermatova
Keyword(s):  
Rock Mass ◽  
Cross Sections ◽  
Tensile Strain ◽  
Rock Fracture ◽  
Strain Analysis ◽  
Surrounding Rock ◽  
Underground Excavation ◽  
Secondary Stress ◽  
Principal Stresses ◽  
Mining Depth

The article presents the studies into the secondary stress field formed in surrounding rock mass around underground excavations of different cross-sections and the variants of principal stresses at a mining depth greater than 1 km. The stress-strain analysis of surrounding rock mass around development headings was performed in Map3D environment. The obtained results of the quantitative analysis are currently used in adjustment of the model over the whole period of heading and support of operating mine openings. The estimates of the assumed parameters of excavations, as well as the calculations of micro-strains in surrounding rock mass by three scenarios are given. During heading in the test area in granite, dense fracturing and formation of tensile strain zone proceeds from the boundary of e ≥ 350me and is used to determine rough distances from the roof ( H roof) and sidewalls ( H side) of an underground excavation to the 3 boundary e = 350me (probable rock fracture zone). The modeling has determined the structure of secondary stress and strain fields in the conditions of heading operations at great depths.

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