Fluid cut-off


Stopping fluid infiltration into a structure or manhole is difficult due to the increase in fluid pressure as the repair process continues. GeoGrout addresses the problem by cutting off the fluid flow from the outside of the structure. Typically the repair process is carried out by advancing a series of injection probes around the structure from the ground surface to the zone in question. The injection process creates a permanent grout plug on the outside of the structure. Since the grout plug is always in compression, an increase in fluid pressure does not affect the repair.

Alternatively, the pressure grouting may be carried out through injection probes advanced through the structure walls. These probes are left in place until the grout sets, then removed and the holes repaired.

GeoGrout has incorporated site specific grout mixes to stop fluid flows upwards from 45 litres/minute (10 gallons/minute) or more, utilizing these techniques.

Sewer Lines

Fluid intrusion into sewer lines, as in manholes and structures, is addressed by advancing grout injection probes from the ground surface to the source of the leak. The injection process creates a permanent grout plug on the outside of the sewer line.

Since the grout plug is always in compression, an increase in fluid pressure does not affect the repair. GeoGrout utilizes video equipment to monitor the pipe enclosure during the repair.

Dams & Canals

In areas where utilities are constructed beneath watercourses, such as dams and canals, the auguring process may disturb the soils around the earth bore. This can create fissure in the soils and eventually lead to piping of the dam or canal water into the earth bore.

GeoGrout has pressure grouted the annular space between the earth bore and pipeline utility, filling any available ground fissures in the process. Due to the pressure gradient associated with these structures, a high strength flow-able cementitious grout is used to assure long term durability.

Abandoned Underground Pipes

With an increase in infrastructure upgrades, the presence of abandoned underground pipes has become more prevalent. This can pose problems such as:

  • Migration of groundwater and hazardous fluids into the pipe enclosure.
  • Potential for build up of explosive gases in the pipe enclosure.
  • Eventual collapse of the pipe and subsequent settlement of the overlaying structures.

Excavation and removal of abandoned underground pipes can be cost prohibitive. Alternatively, Geo Grout has filled insitu pipe enclosures with grout mixes that displace the existing fluids and fill all available voids in the process.

The Payoff

Sewer Systems

Groundwater migration into sanitary manholes and sewer lines increases the overall effluent levels, resulting in increased sewage treatment costs. In cases where this flow cannot be restricted due to head pressures and/or access availability, pressure grouting from the outside of these structures may be the most viable alternative for stopping the flow. GeoGrout has successfully used this technique to curb the flow of groundwater into sewer systems and other underground utilities.

Earth Bores

With an increase in horizontal boring operations, augering beneath earth dams and canals to accommodate pipelines has become quite common. This augering process can cause disturbances in the earth dam or canal berm, which may lead to piping of water from the structure. GeoGrout has addressed this problem by pressure grouting the annular space between the pipeline and the earth bore, utilizing micro fine mixes that seal off ground fissures, preventing water intrusion and subsequent water erosion.

We run a video camera through the section of sewer pipe in question to source the leak. The line is also video monitored during the repair process.

Grout pressures and flow parameters are closely monitored during the grouting procedure. Grouting is continued at each location until zero flow rates are achieved at the maximum allowable pressure.