Rock mass conditions as baseline values for TBM performance evaluation

2021 ◽  
pp. 3-7
Author(s):  
Gerald L. Dollinger ◽  
John H. Raymer
Keyword(s):  
Performance Evaluation ◽  
Rock Mass ◽  
Tbm Performance ◽  
Baseline Values

TBM performance estimation using rock mass classifications

2002 ◽  
Vol 39 (6) ◽  
pp. 771-788 ◽  
Author(s):  
M Sapigni ◽  
M Berti ◽  
E Bethaz ◽  
A Busillo ◽  
G Cardone
Keyword(s):  
Rock Mass ◽  
Performance Estimation ◽  
Tbm Performance

scholarly journals Evaluation on the TBM Performance at a Hydropower Project in Ecuador

2019 ◽  
Vol 24 ◽  
pp. 10-16
Author(s):  
Krishna Kanta Panthi ◽  
Jhonny Encalada
Keyword(s):  
Rock Mass ◽  
San Francisco ◽  
Penetration Rate ◽  
Tunnel Boring Machine ◽  
Quality Parameters ◽  
Hydropower Project ◽  
Tbm Performance ◽  
Rock Mass Quality ◽  
Geological Conditions ◽  
Headrace Tunnel

The aim of this manuscript is to discuss the Tunnel Boring Machine (TBM) performance along the recently constructed headrace tunnel of Minas-San Francisco Hydropower Project in Ecuador. Firstly, the manuscript briefly describes the importance of TBM tunneling and about the Minas-San HPP. Further, discussions are made on the engineering geological conditions along the headrace tunnel. Detailed evaluations are made on the performance of TBM tunneling considering influence of rock mass quality on the TBM penetration rate. The manuscript emphasizes that the knowledge of the rock mass quality parameters and cutter technology available at present are among the key factors that influence the estimation of the net penetration rate of the TBM. It has been demonstrated that the hard to very hard rock masses of high abrasivity that were encountered along the headrace tunnel alignment caused very low penetration giving slow progress, which was not predicted during planning phase design. The authors investigated a fairly good link between TBM penetration and the mechanical strength of the rock mass.

scholarly journals Assessing TBM performance in heterogeneous rock masses

2021 ◽  
Author(s):  
Sarah Sissins ◽  
Chrysothemis Paraskevopoulou
Keyword(s):  
Rock Mass ◽  
Heterogeneous Environments ◽  
Rock Masses ◽  
Tbm Performance ◽  
Machine Performance ◽  
Heterogeneous Rock ◽  
Layered Rock Mass ◽  
Heterogeneous Rock Masses ◽  
Mineral Transport ◽  
The Uk

AbstractA major challenge that TBM performance is requested to deal with for a successful and effective progress is tunnelling through lithologically and geomechanically heterogeneous rock masses. Such heterogeneous environments are common and recent tunnel examples in the UK include the Hinckley Point C offshore cooling tunnels being driven through interbedded carbonaceous mudstone/shales and argillaceous limestone and the Anglo American’s Woodsmith Mine Mineral Transport System tunnel in Redcar Mudstone with beds of ironstone. This inherent geological heterogeneity leads to difficult tunnelling conditions that initially stem from predicting a sound and representative ground model that can be used to preliminary assess the TBM performance. In this work, an exhaustive review of existing TBM Penetration Rate (PR) methods identified that no models address the issue of parameter selection for heterogeneous rock masses comprising layers with different rock strengths. Consequently, new approaches are required for estimating rock mass behaviour and machine performance in such environments. In the presented work the Blue Lias Formation (BLI), which is characterised by its layered rock mass, comprising very strong limestone, interbedded with weak mudstone and shales, is investigated. BLI formation is considered herein being a representative example of lithological heterogeneity. Based on the fieldwork carried out in three localities in the Bristol Channel Basin (S. Wales and Somerset), geological models are produced based on which a geotechnical model is developed, and four ground types are determined. Implications of the current findings for TBM performance are assessed, including faulting, groundwater inflow and excavation stability with a particular focus on both PR and advance rate. A modified approach using the existing empirical models is proposed, developed and presented in this paper that can be used as a guide to determine TBM performance in heterogeneous rock masses reducing the risk of cost and time overruns.

Geological and mechanical rock mass conditions for TBM performance prediction. The case of “La Maddalena” exploratory tunnel, Chiomonte (Italy)

2018 ◽  
Vol 77 ◽  
pp. 115-126 ◽  
Author(s):  
Giacomo Armetti ◽  
Maria Rita Migliazza ◽  
Federica Ferrari ◽  
Andrea Berti ◽  
Paolo Padovese
Keyword(s):  
Rock Mass ◽  
Performance Prediction ◽  
Tbm Performance

scholarly journals Performance Evaluation of Hard Rock TBMs considering Operational and Rock Conditions

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Xiaoyang Zou ◽  
Hui Zheng ◽  
Yongzhen Mi
Keyword(s):  
Energy Efficiency ◽  
Performance Evaluation ◽  
Wear Rate ◽  
Hard Rock ◽  
Vibration Measurement ◽  
Disc Cutter ◽  
Vibration Level ◽  
Operational Parameters ◽  
Tbm Performance ◽  
Cutter Wear

This paper focuses on studying the correlations of the performance of hard rock tunnel boring machines (TBMs) with operational and rock conditions. Firstly, a rigid-flexible coupled multibody dynamic model of an opening hard rock TBM is established for the analysis of its vibration. Then four performance indexes including mean vibration energy dissipation rate, dynamic specific energy (DSE), disc cutter wear rate, and load sharing coefficient are introduced and formulated, respectively, for evaluating the vibration level, excavation energy efficiency, cutter’s vulnerability to wear, and load transmission performance of cutterhead driving system of the TBM. Finally, numerical simulation results of the TBM tunneling performance evaluation are obtained and validated by on-site vibration measurement and tunneling data collection. It is found that operational and rock conditions exert important impact on TBM vibration level, excavation energy efficiency, and structure damage. When the type of rock to be cut changes from soft to hard with operational parameters held constant, TBM performance evaluated by these three indexes deteriorates significantly, and both the decrease of excavation energy efficiency and the increase of cutter wear rate caused by TBM vibration are obvious. This study provides the foundation for a more comprehensive evaluation of TBM performance in actual tunneling process.

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