Rock Excavation Technology and Management in the department of Mining. Engineering ...... B.Tech. Thesis, Department Of Mining Engineering, NIT Rourkela.
INFLUENCE OF STRUCTURAL DISCONTINUITIES ON SLOPE STABILITY Thesis Submitted in partial fulfillment of the requirement for the degree of
MASTER OF TECHNOLOGY (RESEARCH) in ROCK EXCAVATION TECHNOLOGY AND MANAGEMENT by
RAJA S. (110612RT11F02)
DEPARTMENT OF MINING ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA SURATHKAL, MANGALORE – 575025 JULY, 2013
INFLUENCE OF STRUCTURAL DISCONTINUITIES ON SLOPE STABILITY Thesis Submitted in partial fulfillment of the requirement for the degree of
MASTER OF TECHNOLOGY (RESEARCH) in ROCK EXCAVATION TECHNOLOGY AND MANAGEMENT by
RAJA S. (110612RT11F02) Under the guidance of
Dr. Ch. S. N. Murthy Professor Dept. of Mining Engineering
Dr. V. R. Sastry &
Professor Dept. of Mining Engineering
DEPARTMENT OF MINING ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA SURATHKAL, MANGALORE – 575025 JULY, 2013
DECLARATION by the P.G. (M.Tech(Research)) Student
I hereby declare that the Report of the P.G. Project Work entitled “Effect of Structural Discontinuitites on Slope Stability” which is being submitted to the National Institute of Technology Karnataka Surathkal, in partial fulfillment of the requirements for the award of the Degree of Master of Technology (Research) in Rock Excavation Technology and Management in the department of Mining Engineering, is a bonafide report of the work carried out by me. The material contained in this Report has not been submitted to any University or Institution for the award of any degree.
110612RT11F02, Raja S Department of Mining Engineering Place: NITK, SURATHKAL Date: July, 2013
CERTIFICATE
This is to certify that the P. G. Project Work Report entitled “Influence of Structural Discontinuitites on Slope Stability” submitted by Mr. Raja S., (Register Number: 110612RT11F02) as the record of the work carried out by him, is accepted as the P.G. Project Work Report submission in partial fulfillment of the requirements for the award of degree of Master of Technology (Research) in Rock Excavation Technology and Management in the Department of Mining Engineering.
Guide(s)
Dr. Ch. S. N. Murthy Professor Dept. of Mining Engineering
Dr. V. R. Sastry Professor Dept. of Mining Engineering
(Name and Signature with date and Seal)
(Name and Signature with date and Seal)
Chairman - DPGC (Signature with Date and Seal)
ACKNOWLDGEMENT I take this opportunity to express my profound gratitude and deep regards to my guide Dr. Ch. S. N. Murthy, Professor, Department of Mining Engineering, National Institute of Technology Karnataka (NITK), Surathkal for his exemplary guidance, monitoring and constant encouragement throughout the course of this thesis. The blessing, help and guidance given by him time to time shall carry me a long way in the journey of life on which I am about to embark. I have been indebted my co-guide Dr. V. R. Sastry, Professor, Department of Mining Engineering, National Institute of Technology Karnataka (NITK), Surathkal for his valuable time, strict suggestions, cordial advices, lots of knowledgeful thoughts given by him was always invaluable. I also take this opportunity to thank H.O.D., Department of Mining Engineering, N.I.T.K, Surathkal the entire faulty of department for their constant support and guidance through out the course study. I am grateful to Mohan Kumar, Dy. General Manager, S.C.C.L., for his cordial support, valuable information and guidance, which helped me in completing this task through various stages. I am obliged to staff members of Singereni Colleries Company Ltd. for the valuable information provided by them in their respective fields. I am grateful for their cooperation during the period of my assignment. I am thankful to staff members of Department of Mining Engineering, N.I.T.K, Surathkal, especially Mr. Chandrahasa Rai, for his constant advice throught the course of study. The informal support and encouragement of many friends has been indispensable, and I would like to particularly to acknowledge the contribution of Manjuanth A., Modi Jemishkumar Vijaykumar, Naresh Babu D., Ravichandran Nannuri, Anil Kumar K, Dhanabal, Dhanaraju S & Arun Raj.
Special thanks to my School Teachers, College Lecturers without them nothing was possible in my life.Lastly My parents, Sabapathy S., Amudha S., My sisters, Nithya Mohan, Roopa Lakshmi S., and my uncle, B. K. Mohan have been a constant source of support – emotional, moral and of course financial – during my postgraduate years, and this thesis would certainly not have existed without them and thanks to the Almighty God .
- Raja S., NITK, Surathkal, July, 2013
ABSTRACT Rock mass is a non-homogeneous and an anisotropic material built up of smaller and larger block of rock, whereas the presence of structural discontinuities in the rock mass is major concern. The concept of rock mass characterization is very important for the success of any engineering excavations made in the rock mass. A detailed study on the presence of joints and its orientation and discontinues in the rock mass exposed is very important because, it is likely to have greater influence on both stability aspects as well as fragmentation of the rock mass. Already established rock mass classifications like rock mass rating, Q-classification etc., requires number of geological parameters along with physic-mechanical properties of rock. Determination of the geological parameters in a conventional method requires careful measurements on site, which is a very time consuming process. With advent of new technologies, the images were taken in the site and processed in software. The number of opencast coal mines is steadily increasing as compared to underground mines due to low gestation period, higher productivity, and quick rate of returns. On the otherhand, opencast mining attracts environmental concerns such as air pollution, water pollution, solid waste management, land degradation and socio-economic problems. In addition to that a large number of opencast coal mines, whether large or small, are now-adays reaching to deeper mining depths. Hence, analysis of bench slopes and ultimate pit slope design are very important. As slope failure causes loss of production, extra stripping cost for recovery and handling of failed material, dewatering the pits and sometimes progresses to mine abandonment or premature closure, loss of life. A study was carried out in Prakash Khani Opencast Mine –IV, Manuguru area, M/s The Singereni Company Colleries Limited (SCCL) to find the influence of structural discontinuities on slope stability. An attempt is made in this project to assess the rock mass characterization using SIROVISION software and the influence of structural discontinuities on slope stability using PLAXIS-2D software. A mathematical model is developed from multiple regression analysis. The empirical relationship developed is not aimed at replacing the any existing methods, but rather as a quick and easy method to i
estimate the FOS reported in this investigation. Based on the results acquired by the analyses using SIROVISION and PLAXIS-2D, a comparative conlusion has been drawn, it is found that RMR of the mine was ranging from very poor to fair due to the presence of large number of discontinuities and the presence of discontinuities in slope decrease the FOS, which in turn suggests that it affects the slope stability. In case of ideal benches, the FOS is ranging from 3.205-1.3 for different slope angle, bench heigth and bench width, it states the bench is stable. In case of single set of discontinuities and two sets of discontintuities, the FOS is ranging from 2.683 to
