Compaction grouting is a specialized process that requires significant training and experience to execute correctly. Property owners and building contractors should only work with licensed & insured experts.
Compaction grouting is ideal for stabilizing granular soils on construction sites and addressing foundation settlement in existing commercial structures. It is also an effective method for reducing the risk of liquefaction in earthquake-prone areas and for projects with limited access that prohibit vibration compaction methods.
Know Your Requirements
Soil conditions and compaction specifications often don’t call for the highest-powered, hardest-hitting machine. Such machines can over-compact the soil, causing damage and requiring costly repairs later.
Compaction grouting works by creating a series of bulb-like structures underground in a grid pattern and injecting a high-density cement mixture through drilled casings. This method stabilizes granular soils and fills voids in the subsurface, eliminating the loose and crumbly conditions that can cause foundation settlement.
Compaction grouting also allows engineers to design for new construction more economically by strengthening the soil to withstand higher bearing pressures. As an added benefit, this technique can help reduce the need for future repair and maintenance of a foundation or structure. A contractor specializing in this service has the equipment, tools, and expertise to tackle complex soil remediation projects. Using this technology can significantly reduce the cost of a building project.
Know Your Materials
Compaction grouting involves displacing and densifying soft granular soil by injecting a high-density aggregate cement mixture at controlled depths via a drilled or driven injection casing. The process can stabilize fine soil, prevent sinkholes, and reinforce foundation structures.
Complemented by skin friction between the grout mass and the soil, the technique offers superior performance in various applications. It can support new construction or lift and level structures on weak soils. It can also mitigate liquefaction potential and reduce the risks of structural damage following severe inclement weather events.
The equipment works from the bottom up, with each aggregate grout stage creating a “grout bulb.” Soil is improved by reducing pore water pressure and increasing the load-bearing capacity of the weak material. Each grout bulb is placed in a grid pattern following soil conditions and treatment depths. The injection rate is adjusted to ensure a consistent increase in the ground’s strength without exceeding its tolerance limits.
Know Your Equipment
Compaction grout for weak soils requires specialized equipment and technicians. Soil probes, soil anchors, and foundation structural elements are typically spaced on eight-foot centers, but this varies from site to site.
In addition to improving ground strength, compaction grouting can be used for several geotechnical challenges, including settlement control and structural releveling. Using controlled displacement, high-strength mortar-like grout is injected into the soil zone through drilled casings at a fixed depth until a pre-determined minimum injection pressure or grout volume is reached.
The grout displaces the surrounding soft granular soil, compacting and densifying it, forming an underground bulb-like structure. The grout bulbs increase the soil’s bearing capacity and resist liquefaction, which allows structures and their foundations to be lifted.
CGS’s crew drilled at over 626 grout locations on the job site, working through snow and cold temperatures, and was able to keep project delays to a minimum. Despite the weather, CGS completed its work on time and under budget, meeting the owner’s goal for completion.
Know Your Contractor
If the equipment you choose for your compaction grouting project generates vibration, it could cause damage to nearby structures. This is why selecting a qualified geotechnical contractor with a high experience level is essential to complete this work.
In compaction grouting, stiff, low-mobility soil/cement mixtures are injected under pressure. The grouting process raises, lifts, or relevels concrete foundations and slabs, reinforces excavation support walls, fills rock cracks, mitigates liquefaction potential, constructs underpinning, remediates threatening sinkholes and fills water cutoff walls.
Engineered Solutions of Georgia (ESOG) specializes in commercial compaction grouting services. We use our expertise and engineering capability to design a compaction grouting program that fits your project. ESOG has completed numerous commercial projects requiring compaction grouting in Atlanta and the Southeast. We’ve used this advanced technology to repair and stabilize weak soils, underpin existing foundations, lift and relevel slabs, provide excavation support, fix fractured concrete, and even create temporary water cutoff walls for tunneling.
