K & C POWER HOUSE REPAIR

59 CLEAR LAKE ROAD NORTH, KAPUSKASING, ONTARIO, P5N 2X7

TEL: (705) 337-5211

FAX: (705) 335-6364

SOIL STABILIZATION - CEMENT AND CHEMICAL GROUT

When sand and gravel appear in combination or in alternative layers, K & C POWER HOUSE REPAIR has found that the most efficient and least costly procedure for stabilization or arresting water movement is to use a combination of chemical and cement grouts that are compatible, i.e., that can be mixed and pumped alternatively or in combination through the same equipment and inserts as job conditions indicate.

Multiurethane products are ideal for this situation. Multiurethane products will penetrate almost any sandy material that water will move through and stabilize it while providing greatly improved strength. And where the foundation material is open-work gravel, non-shrinking grout will strengthen the material to near mass-concrete quality.

K & C Power House Repair has developed a strong working relationship with Multiurethanes Ltd., because Multiurethanes offers Canada's most comprehensive range of injection materials, equipment and accessories used for the repair and/or waterproofing of concrete structures. In mining and geotechnical applications, their products are used for soil consolidation, water cut-off and grouting of rock fissures.

(i) In December of 1994, K & C Power House Repair and Multiurethanes Ltd., were called to AUR Resources, Project Louvicourt, where two diamond drill holes from the adjacent abandoned and flooded mine were intersected by longhole drilling from the ventilation raise. The grouting strategy was to gradually reduce the water:cement ratio to thicken the grout and then to introduce CELBEX 653 to coagulate the thickened grout. At both water inflow locations, the longhole which intersected the diamond drill hole was sealed with a metal plug (torpedo) and held in position by the longhole drill. Peripheral leakage was eliminated by hammering small wooden wedges between the metal plug and the sides of the blasthole. Conventional grout plugs were installed into adjacent holes which had intersected the main water flow hole. One grout plug was equipped with a grout header and pressure gauge and connected to the bottom end of the 1" threaded grout pipe using a high pressure grout hose. The valves on the grout plug and grout header were opened and the grout pipe was allowed to fill with water. Static water pressure prior to grouting was 395 psi in the lower hole and 380 psi in the upper hole. During grouting operations, grouting pressures at the grout plug increased by 20 - 30 psi as coagulated grout was pushed through the drill holes. Samples of the various grout batches were taken for monitoring the cure rate of the grout. In addition, samples of grout from the grout header were also taken to verify the grout consistency and quality. The combined use of bentonite and CELBEX 653 created a soft plastic grout with the consistency of toothpasteafter the grout has been allowed to stand for a brief period of time. The coagulation of the grout was observed in the grout mixing tubs and in the pump suction pail whenever the grout remained in the tubs due to slow pumping rates. The end result for both holes was that sufficient quantity and quality of grout was pumped into both holes to create an effective and permanent seal over the full length of both diamond drill holes.

(ii) In February of 1995, K & C Power House Repair and Multiurethanes Ltd., were again called to AUR Resources, Project Louvicourt, where leaking water from the sump in the pump room was travelling through cracks in the rock and penetrating the shotcrete creating serious leaks in the pump room. When first observed, it was anticipated that a series of large cracks were involved, thus suggesting that a cement grouting operation would be most appropriate. A series of 6 ft, 8 ft and 12 ft holes were drilled using a stoper. Grout plugs were installed and the drilled holes were water tested. Several of the drill holes were water tight with the remaining holes contributing to relatively small water leaks. After considering the large number of grout plugs which had been installed in this area, without significant effect, it was determined that it would be very difficult to locate the primary rock fissures feeding water from the sump to the pump room. It was then decided to attempt to polyurethane grouting operation to seal obvious water exit locations in a effort to direct water, through those holes which had a positive water take, to the major fissures leading back to the sump. The initial results of the polyurethane grouting operation was made through adjacent small diameter (3/8") drill holes. This was successful in stopping and/or redirecting water leakage by sealing porous areas of the shotcrete. On the last 3 days, the grouting was performed under full hydrostatic head conditions. The end result was significant reduction in the overall volume of water leakage in the pump room.