IN-SITU EVALUATION OF HAZARDOUS WASTE BARRIERS USING GUIDED SEISMIC WAVES

EVALUATION OF SUBSURFACE CONDITIONS IS EXTREMELY IMPORTANT IN DESIGNING, MONITORING, AND REMEDIATING HAZARDOUS WASTE DISPOSAL SITES. OF PARTICULAR IMPORTANCE TO SUCCESSFUL CONTAINMENT OF CONTAMINANTS IS THE INTEGRITY, STABILITY, AND OVERALL PERFORMANCE OF SUBSURFACE BARRIERS. THE UNCERTAINTY SURROUNDING THE PROPERTIES AND PERFORMANCE OF THESE BARRIERS IN-SITU IS WELL RECOGNIZED. CURRENT GEOPHYSICAL METHODS UTILIZED FOR SUBSURFACE INVESTIGATIONS AT HAZARDOUS WASTE SITES LACK THE ABILITY TO DEFINE AND RESOLVE THE PROPERTIES OF SUCH STRUCTURES, DUE TO THE LONG WAVELENGTHS AND LOSSES IN THE OVERBURDEN. THE OBJECT OF PROPOSED RESEARCH IS TO EXPLOIT THE POTENTIAL APPLICATION OF GUIDED SEISMIC WAVES, SINCE THESE WAVES ARE EITHER "TRAPPED" IN THE ZONE OF INTEREST (SEAM WAVES), OR THEY CAN PROVIDE FAVORABLE TRANSMISSION TO THE SURFACE (TUBE WAVES). THE RESEARCH WILL SEEK TO EXTRAPOLATE EXISTING GUIDED WAVE THEORY AND APPLICATION DATA TO THE RANGE OF PARAMETERS OF INTEREST AT HAZARDOUS WASTES SITES. THE RESEARCH WILL ALSO TO DEFINE THE APPLICATION CONDITIONS AND ASSOCIATED PHYSICAL PROPERTIES IN A MANNER WHICH PROVIDES A CLEAR BASIS FOR THE DEVELOPMENT OF INSTRUMENTATION BASED ON GUIDED WAVE PHENOMENA. THESE TWO ACTIVITIES WILL BE FOLLOWED BY A PILOT 1/5 SCALE FIELD DEMONSTRATION/EVALUATION OF A SPECIFIC INSTRUMENT CONCEPT.