An overview of the entire area before grouting began. Notice the steel pilings on either side of the floor.
An overview of the entire area before grouting began. Notice the steel pilings on either side of the floor. Chemical grouting procedures are frequently used to stop leaks in subterranean pipes, earth or concrete dams, stabilize or firm-up loose soil through pressure grouting and permeation grouting. These repairs use a type of grout known as hydro-active grout that begins to harden or “fire” when it comes into contact with water.
DeNeef Hydro Active Cut grout is carefully mixed so that it activates or “fires” at the right time after water is introduced.
Hydro-active grout consists of two parts: resin and a catalyst which are mixed in a special grout machine and pumped into pre-drilled grout ports through a device know as a packer and into the void areas. After all the cracks and fissures are filled and satisfactory pressure is reached the packer is closed off and pumping stops. After a predetermined amount of time the grout will begin to fire and the packer can be removed. The grout now activates and expands filling voids and compressing soil effectively stabilizing the area. This chemical grout now becomes part of the soil and has no harmful effects on the environment.
Chemical grouting can also used on a smaller scale to repair leaking swimming pools. Holes or ports are drilled in a cross stitch pattern along the crack, packers are installed to contain the grout then it is pumped into the packer. After the grout fires the packers can be removed and the leak is stopped.
One of the advantages to chemical grouting is the fact that it can be used to stop a leak while it is leaking water. Basically this is done by varying the mix ratio to give different firing delays so that the grout begins to cure as it makes it to the leak and upon hardening it stops the leak and becomes an integral part of the surrounding material.
An Air-track drilling the ports that were later cased with a plastic casing that stays in the port after grouting.
The growing number of abandoned coal mines has increased the need of abandoned mine grouting. Subsided coal mines can cause sink holes and other major property damage.
Mine Grout RepairThe process of grouting a subsided mine can take anywhere from a matter of days to several months, depending on the mine’s size and severity of the subsidence. The only sure way to locate an abandoned mine is to drill. These abandoned mines, when subsided can cause major property damage to homes, roads, even endangering lives. One of the dangers of abandoned coal mines is the possibility of continuous fire burning inside belching out harmful gases.
Grout being pumped through a tremie pipe into a void created by an abandoned mine in Wyoming County, WV.
How Mine Grouting Works?
Mine Grout SealerMost of this can be stopped by grouting the abandoned coal mines. Old maps are used to determine the general area of the abandoned mine and drilling can begin. Holes, also known as grout ports are drilled in predetermined locations down to the mine shaft.
Mine Grouting RemediationIn some cases, a “down-the-hole” (DTH) camera is used to verify the void ranges. A plastic pipe known as “casing” is inserted into the drill hole to prevent the hole from collapsing. The proper grout mix is then batched either on site or delivered. The grout is injected into the ports, filling the voids and stabilizing the area while preventing subsidence. Again a DTH camera may sometimes be lowered into the grout ports to verify proper grout flow.
Preparations in the early stages, placement of the tremie, witness pipes and the bulkheads in progress. Next, dirt will be placed in front of the bulkheads before grouting for added strength.
Due to the limited technology of the past, there are many abandoned auger mines that are only 100’-150’ deep. With current technology Highwall Mining machines can reach well over 1,000’ allowing mining of once unreachable coal. In order for the Highwall miners to safely mine this coal, some of the old shafts have to be grouted full. This additional grouting is necessary to support the areas near the new cuts to prevent collapsing.
Grouting completed and after given time to set up the excess dirt and pipe is removed and the highwall is ready for the highwall miner to begin cutting.
Marco Concrete Lifting has many years experience with auger mine grouting. We offer the newest techniques and we bring with us vast experience and an excellent safety record. Please contact us for assistance in the planning and implementation of your auger mine grouting project.
Auger Mine Grouting Procedure:
To begin, bulkheads are placed across the portal and a tremie pipe is placed through the bottom of the bulkhead extending several feet back into the shaft, a smaller witness pipe is also placed through the bulkhead near the top equipped with a shutoff valve. This valve allows air displaced by the grout to escape. A grout/concrete pump is used to pump grout into the auger hole via the tremie pipe. Once full and rich grout is observed exiting the witness pipe, the shutoff valve is closed and the shaft is totally full of grout (see diagram below).