Stability Evaluations of Selected Room and Pillar Rock Salt Mines by Using Flat Jack Technique-A Case Study

Authors

  • Yasir Majeed Mining Engineering, UET Lahore
  • Nasir Abbas Mining Engineering, UET Lahore
  • Muhammad Zaka Zaka Emad Mining Engineering, UET Lahore

DOI:

https://doi.org/10.17159/

Abstract

Stope and pillar mining method is commonly employed for the extraction of rock salt in underground mines. Pillar stress is a major concern in mines as it is directly related to stability, and recovery of mineral. In this study flat jack method was used to measure pillar stresses in three underground rock salt mines including Khewra, Warcha and Kalabagh selected from the Eastern, Central and Western Salt Range, Punjab of Pakistan. The field work included determination of in-situ stress, in-situ elastic modulus, recording of field variables [pillar length (L), pillar width (W), pillar height (H), width of opening (WOP), width to height ratio (W/H) and overburden height (OB)] and collection of salt boulder samples. The geo-mechanical properties of rock salt [uniaxial compressive strength (UCS), Young’s modulus, Brazilian tensile strength (BTS) and density] were also determined to estimate overburden stress, pillar strength and factor of safety (both estimated and actual). It was found that the measured pillar stresses in the Salt Range are proportional to the overburden stress values with their magnitude ranging from 4.38 MPa in Kalabagh  to 11.97 MPa in Khewra and the pillars were found to be stable. Further regression analysis was performed to develop statistical model between in-situ elastic modulus and laboratory static modulus.  Finally a quick guideline chart was developed to find out suitable length of pillar for a given span and required level of safety.

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Author Biography

  • Muhammad Zaka Zaka Emad, Mining Engineering, UET Lahore

    My work experience includes teaching and research at McGill University, Montreal, and UET Lahore, Pakistan. In May 2007, I joined the Department of Mining Engineering, UET Lahore as a Faculty Lecturer. I taught courses including Intro to Mining, Rock Mechanics, Engineering Geology, Mine Survey lab, and Slope stability. I was also assigned to prepare and invigilate examinations, grade, and prepare the results. I organized and supervised two weeks of field survey camps in the summer at Abbottabad, Khyber Paktoon Khawa (Years 2007 to 2010). I also took part in the accreditation process for the Mining Engineering program.

    In 2010, I secured a Ph.D. position at McGill University, which I joined in Fall semester 2010. From 2010 to 2013, I worked on a collaborative research grant for my Ph.D. research. The case study mine was Birchtree mine in Thompson, MB, and the funding agencies for the project were NSERC and Vale. In the process, I published my research in Journals and presented it at conferences. McGill University awarded me excellence in research awards in 2012, 2013, and 2014. I was also awarded a medal for excellence in research by the McGill University. I have also been a part of leading and organizing training workshops at McGill University. I also carried out field trips to Val-d’Or, QC, Abitibi, QC, and Sudbury, ON. After my Ph.D., I continued as a Post-doctor fellow at the Mine Design Lab at McGill University, where I worked with Vale mines in Sudbury.

    In 2014, I returned to Pakistan and joined Mining Engineering Department at UET, Lahore. I taught courses including Rock Mechanics, Ground Control Engineering, Explosives Engineering, my Power Drainage, and Materials Handling, Rock Slope Engineering, Stability of Underground Openings, Geological Investigation & Ground Characterization, and Tunnel Design. I also worked on upgrading existing courses and developing new ones for undergraduate and postgraduate programs. I also conducted an industry survey and performed benchmarking of the curriculum. I served as a member of the accreditation committee for preparing and organizing accreditation visits on Outcomes-Based Education (Washington Accord) criteria 2017, 2018 & 2020. I served in the committee for drafting continuous quality improvement (CQI) policy and mechanism in the department. I initiated and executed a new MSc program “Tunneling and Underground Excavation Engineering” in 2017. I also organize and carry out field trips for the 5th-semester class every year. I also supervised nine MSc thesis and eight final year projects. Currently, I am supervising three Ph.D. students and two MSc students. I also secured and managed funded competitive research and training grants from national and international organizations. I published a total of twenty-one journal publications and seventeen conference papers. I also worked on surface and underground mining projects to solve their problems with in-kind support from the industry.

Published

2026-04-15

Issue

Vol. 124 No. 8 (2024): SAIMM Journal

Section

Papers of General Interest

License

Copyright (c) 2024 Yasir Majeed, Nasir Abbas, Muhammad Zaka Zaka Emad

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