Save, Neelambari R (2004-12). Ground penetrating radar technique to locate coal mining related features: case studies in Texas. Master's Thesis. Thesis uri icon

abstract

  • The goal of this research project is to identify the efficacy of the ground
    penetrating radar (GPR) technique in locating underground coal mine related subsidence
    features at Malakoff and Bastrop, Texas. The work at Malakoff has been done in
    collaboration with the Railroad Commission of Texas (RRC). RRC has been carrying
    out reclamation of abandoned underground coal mines at Malakoff since the early
    1990??s. The history of the specific mining operations (at Malakoff and Bastrop) that
    took place in the early 1900??s has been difficult to ascertain; therefore, the use of a
    geophysical techniques like ground penetrating radar to identify hidden voids and
    potential subsidence features is vital for future reclamation process. Some of the
    underground mine workings at the field site have collapsed over time affecting the
    topography by creating sinkholes. GPR data, employing 25 MHz, 50 MHz and 100
    MHz frequency antennae, have been collected in common offset patterns and azimuthal
    pattern. GPR data indicate the mine tunnels possibly connecting existing sinkholes by
    radargram hyperbolae that correspond with mine openings observed visually or during
    reclamation. This study also denotes the importance of understanding the variable
    physical properties of the stratigraphy, which could lead to false alarms by
    misinterpretation of the radar signals. Natural and man-made above-ground structures
    cause obstructions in data collection, and hence an optimal design is required for each
    survey. RRC successfully ground-truthed the data during its reclamation process. In
    turn, the acquired geophysical data helped to guide the reclamation. At Bastrop, GPR
    data along with historical documentation led to the conclusion that coal mining did exist
    in this region but is not a major concern to the immediate stability and safety of the field
    site. It can be concluded from both the studies that the GPR technique identifies
    anomalous shafts/tunnels possibly connecting potential failure.

publication date

  • December 2004