Subsurface & Jet Grouting in Houston, TX
Grouting soil and rock masses extend the technology from construction to environmental rehabilitation. Subsurface grouting is done for stability or hydraulic control, Geotechnical applications have long been common in foundation work. Environmental uses have come into their own in the last decade, as RBCA laws have allowed risk-based corrective actions for subsurface problems, and legitimized containment in place.
The principal advantage that grout curtains have over slurry walls and sheet pile barriers is that grout can target just the zone of interest, rather than having to be set all the way to surface. Further, grout can be injected by borings angled under structures, using compact equipment, allowing installations around active plant. Techniques in subsurface grouting include the following:
|• Permeation Grouting of Natural Granular or Fracture Porosity
||• Creating Grout Lenses in Hydraulic Fractures
Low viscosity grout can be injected at low pressure to permeate granular material and give cohesion to loose sand under a structure or create a groundwater barrier. Grouts varying from expansive, quick setting urethanes to fly ash can be used to plug natural joints. Multi-stage grouting can be used to plug joints and then matrix porosity in a fractured sandstone.
Pier setting in contaminated ground can be facilitated by pre-grouting drilling locations to gel groundwater, to prevent flow into the borehole without casing.
Grout lenses can be injected at a pressure higher than the overburden load, to create a subsurface cap to a contaminated zone and inhibit vertical migration of groundwater.