MINE4123: Mining Research Project II Final Thesis (Revised): Influence of Geotechnical Properties on the Run-out Process at Bingham Canyon Slope Failure Commissioned by: Prof. Marc Ruest Course Coordinator: Dr. Christopher Leonardi Date of Submission: 08th November 2016 Submitted by: Alfred Septian UQ Supervisor: Marcelo Llano Serna i ACKNOWLEDGEMENTS I would like to express the deepest gratitude to my advisor Marcelo Llano Serna for his full dedication, to support, commit, expert guidance, understanding and encouragement throughout my study and research. Without his incredible patience, commitment, and timely wisdom and counsel, my thesis work would have been a frustrating, time consuming, and overwhelming pursuit. Also, I express my appreciation to Prof. Marc Ruest for providing me with this astounding thesis project, for the potential breakthrough of the thesis that I undertake this year. His time was valued greatly. Finally, I would like to thank my parents, and peers for their unconditional love and support during this year upon completing my thesis. I would not have been able to complete this thesis without their constant love and encouragement. ii SUMMARY The Bingham Canyon Mine is located approximately 30 km south-west of Salt Lake City in Utah, USA. Bingham Canyon mine is located at Oquirrh Mountains at late Palaeozoic period (between 260 and 320 million years ago). Bingham Canyon Mine dependent on hydrothermally altered and mineralised plutonic body referred to as Bingham Stock. The mineralisation that formed the deposit is mainly chalcopyrite and bornite. The Kennecott failure occurred on the 10th of April 2013. The first event happened at 03:30 am UT from the middle bench of the mine, where infrastructures located. The second event occured at 05:56 am UT from the top bench of the pit. There are no casualties in both events. However, there are damaged trucks even with the predicted run-out before the event take place. This project covers mainly on numerical analysis using a tridimensional limit equilibrium method to define suitable failure surfaces and later the Material Point Method (MPM) to describe the kinematics of the landslide. The relevance of this analysis relies on the potential of defining a framework of actions that may give insights on the preparation to attend the operative needs in a failed slope and mitigate its adverse effects. The volumes of the first failure are approximately 24Mm3 volumes with 0.98 for FOS with 3D Bishop’s search method. The volumes of the second failure are approximately 22Mm3 volumes with 0.89 for FOS with 3D Bishop’s search method. In comparison, the second failure gives lower FOS rather than the first one due to some of the mass that move from the first failure acted as support for the mass that moved at the second failure. Kinetic energy of the first slide shows a decrease value at t=40s. It is suspected that the failure material points hit the pit wall that causes the material points to change direction throughout the run-out. The kinetic energy of the second slide is constant throughout the event due to the path that created by the first slide cause the failure path to be smoother. Same behaviour occurred with the velocity analysis for both first and second failure, and it is in close agreement with two- dimensional and LFH past research. Sensitivity analysis was conducted by changing the geotechnical properties of the failure surfaces to observed the changes that will affect the run-out of the landslide. A tridimensional approach is able to describe better due to complex topography than two-dimensional simplifications. The numerical analysis used to give insight in predicting the possible failure that might occur on site, to help assess the risk assessment and safety. iii STATEMENT OF ORIGINALITY I hereby declare that this research project proposal is my own work and that it contains, to the best of my knowledge and belief, no material previously published or written work by another person nor material which to a substantial extent has been submitted for another course, except where due acknowledgement is made in the report. Signed, Alfred Septian TABLE OF CONTENTS Acknowledgements .................................................................................................................. iii Summary ................................................................................................................................... ii Statement of Originality ........................................................................................................... iii 1. Introduction ........................................................................................................................ 1 Aims and objectives .................................................................................................. 1 Scope ......................................................................................................................... 1 Significance and relevance to industry ..................................................................... 2 Background ............................................................................................................... 3 Geology ......................................................................................................... 4 Geotechnical properties ................................................................................. 6 Mining activities ........................................................................................... 8 Massive pit wall failures ............................................................................... 8 Problem definition .................................................................................................... 9 Methodology ........................................................................................................... 12 2. Project Management ......................................................................................................... 13 Introduction ............................................................................................................. 13 Key tasks ................................................................................................................. 13 Current status of research project ........................................................................... 14 Future work ............................................................................................................. 14 Project budget ......................................................................................................... 14 3. Literature Review ............................................................................................................. 15 Landslide ................................................................................................................. 15 Definition .................................................................................................... 15 Landslide parameters .................................................................................. 15 Landslide causes ......................................................................................... 15 Impact of landslide ...................................................................................... 15 Economic impact of landslide ..................................................................... 16 Landslide classification ............................................................................... 16 Type of materials ........................................................................................ 16 Type of movements ..................................................................................... 17 Rock Avalanche ...................................................................................................... 17 Run our kinematics ................................................................................................. 18 3D slope stability .................................................................................................... 21 Limit equilibrium method ....................................................................................... 22 Simplified Bishop’s method........................................................................ 22 MPM (MATERIAL POINT METHOD) ................................................................ 23 Introduction ................................................................................................. 23 Eulerian-Lagrangian .................................................................................... 24 FEM vs MPM.............................................................................................. 26 NairnMPM .............................................................................................................. 28 4. Geotechnical Modelling ................................................................................................... 30 Scoop3D single surface optimisation ..................................................................... 35 Slip direction vs FOS .................................................................................. 35 Elevation z vs FOS vs volumes................................................................... 36 Radius r vs FOS vs volumes ....................................................................... 37 5. Numerical Modelling ......................................................................................................