Numerical analysis of the effects of external blasts on tunnels
department or school: Applied Science, Faculty of
department or school: Mining Engineering, Keevil Institute of
data provider: DSpace
degree campus: UBCV
creator: Mitelman, Amichai
issued: 2015-06-08T21:31:31Z
issued: 2015
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: This thesis presents the application of the finite-discrete element method for simulation of the impact of external blast loads on tunnels in rock. An extensive database of field tests of underground explosions above tunnels is used for calibrating and validating the proposed numerical method. The numerical results are shown to be in good agreement with published data for large-scale physical experiments. 1D and 2D model results are compared to analytical spalling equations and to the field test findings. It was found that only the 2D models are suitable for support design. The influence of rock strength on tunnel durability to withstand blast loads is investigated. It was found that higher rock strength will increase the tunnel resistance to the load on one hand, but decrease attenuation on the other hand. Thus, under certain conditions, results for weak and strong rock masses are similar. Finally, a discussion on tunnel support design to withstand blasting is presented. A distinction between heavy spalling and light rockfall is made based on an estimation of the ratio of peak stress of the arriving wave to the rock tensile strength. Accordingly, different design approaches are suggested: for heavy spalling a low impedance isolating layer between the tunnel liner and surrounding rock is recommended. For light rockfall, a simplified static FEM analysis procedure is presented.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/53803
note: NUMERICAL ANALYSIS OF THE EFFECTS OF EXTETNAL BLASTS ON TUNNELS by Amichai Mitelman A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Mining Engineering) THE UNIVERISTY OF BRITISH COLUMBIA (Vancouver) June, 2015 © Amichai Mitelman, 2015 ii Abstract This thesis presents the application of the finite-discrete element method for simulation of the impact of external blast loads on tunnels in rock. An extensive database of field tests of underground explosions above tunnels is used for calibrating and validating the proposed numerical method. The numerical results are shown to be in good agreement with published data for large-scale physical experiments. 1D and 2D model results are compared to analytical spalling equations and to the field test findings. It was found that only the 2D models are suitable for support design. The influence of rock strength on tunnel durability to withstand blast loads is investigated. It was found that higher rock strength will increase the tunnel resistance to the load on one hand, but decrease attenuation on the other hand. Thus, under certain conditions, results for weak and strong rock masses are similar. Finally, a discussion on tunnel support design to withstand blasting is presented. A distinction between heavy spalling and light rockfall is made based on an estimation of the ratio of peak stress of the arriving wave to the rock tensile strength. Accordingly, different design approaches are suggested: for heavy spalling a low impedance isolating layer between the tunnel liner and surrounding rock is recommended. For light rockfall, a simplified static FEM analysis procedure is presented. iii Preface This thesis is original and independent work done by the author. The author was the lead author in the two published manuscripts based on the work for this thesis and the co-author was the thesis supervisor. The paper “Modelling of…
has type: Thesis/Dissertation
date issued: 2015-09
is shown at: 10.14288/1.0166297
language: eng
degree discipline: Mining Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivs 2.5 Canada
rights URI: http://creativecommons.org/licenses/by-nc-nd/2.5/ca/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/53803