INVESTIGATION OF TECHNIQUE FOR ISOLATING CHEMICAL WASTE SITES BY HYDRAULIC FRACTURING IN SOIL

CONSTRUCTION OF EXTENSIVE IN-GROUND BARRIERS CAN BE USED FOR: ISOLATING CHEMICAL WASTE SITES, CONTROLLING SEEPAGE IN DEEP EXCAVATIONS, ISOLATING STRUCTURES FROM VIBRATION; AND CREATING CLOSED UNDERGROUND HYDROLOGIC RESERVOIRS. PRESENT TECHNIQUES ARE ONLY ABLE TO PRODUCE VERTICAL BARRIERS. THEREIS A TREMENDOUS NEED PARTICULARY IN THE CHEMICAL WASTE ISOLATION APPLICATION FOR BOTTOM BARRIERS AS WELL. THE BLOCKDISPLACEMENT TECHNIQUE HAS BEEN CONCEIVED TO FILL THIS GAP BY PLACING A BARRIER BOTH AROUND AND BENEATH A LARGE TRACT OF LAND. THE TECHNIQUE INJECTS LOW PERMABILITY MATERIAL IN A SLURRY STATE INTO NOTCHED INJECTION WELLS PROPAGATING HORIZONTALLY-ORIENTED SEPARATIONS AND LIFTING THE BLOCK OF OVERLYING GROUND IN THE PROCESS. THE RESULTS OF A FIELD TRIAL OF THE CONCEPT WERE VERY PROMISING BUT DID NOT PERMIT RIGOROUS DOCUMENTATION OF BARRIER CONTINUITY. IT IS THE OPINION OF THE SCIENTIFIC, ENGINEERING, AND CONSTRUCTION COMMUNITIES THAT FURTHER TESTING IS NECESSARY TO ESTABLISH ASCIENTIFIC UNDERSTANDING OF THIS PROCESS AND TO ASSESS ITS APPLICABILITY TO OTHER GEOLOGIC CONDITIONS. SUCH AN UNDERSTANDING IS A PREREQUISITE TO ACCEPTANCE OF BLOCK DISPLACEMENT BY THE CHEMICAL WASTE CLEANUP INDUSTRY. IT IS OUR INTENT TO BRIDGE THIS GAP BY PROVING THE CONCEPT IN PHASE I, STUDYING THE FEASIBILITY OF PRACTICAL APPLICATION IN PHASE II, AND MITIGATING DEFICIENCIES IN AVAILABLE HARWARE IN A PRIVATELY FUNDED PHASE III.