Compaction Grouting
COMPACTION GROUTING IS A PROCESS THAT "ADDRESSES THE CAUSES FOR STRUCTURE AND FOUNDATION SETTLEMENT, NOT THE SYMPTOMS." THE PROCESS IMPROVES LOAD BEARING CAPACITIES, DENSIFIES WEAK SOILS, AND POORLY COMPACTED FILLS, THE CAUSES FOR SETTLEMENT PROBLEMS.
- FOUNDATION SETTLEMENT
- STRUCTURE RAISING
- SOIL DENSIFICATION
- SETTLEMENT PROBLEMS
Compaction Grouting Uses:
- Pipeline Support
- Sink Hole Filling
- Poorly Compacted Fills
- Roadway Raising
- Soft Ground-Tunneling Excavation
- Re-leveling Settled Structures
- Improper De-Watering
- Broken Utilities
WHAT IS COMPACTION GROUTING?
Compaction grouting is the injection of a low mobility, stiff cement grout into soil to improve load bearing capacity. The soil is densified, thus increasing its bearing capacity, or ability to support a structure. Compaction grouting was developed as a corrective measure to address the causes for structure settlement versus the symptoms. Compaction grouting has a long history of success for soil densification and remediation of structures that have settled. The process consists of installation of injection pipes to the bottom of the zone being treated.
For structure raising, injecting of a “bulb” of stiff grout into the soil displaces and densifies the soil urging it upwards in a controlled manner. Pumping pressures of 1,000 p.s.i. are carefully regulated to stabilize and then, if desired raise the structure in a controlled manner. The process densifies weak soil, fills soil voids, and drives out perched water, stabilizing the foundation or structure.
HOW IT'S DONE
Steel pipes are either drilled or driven into the zone to be stabilized, deep below the foundation or structure to be raised. They are then retracted a few inches to open the end of the injection pipe to allow flow of the grout. As the grout expands in a homogenous bulb, radial forces displace, and thus compact the surrounding soils. Slow injection prevents soil fracturing and allows water to dissipate as the structure is gradually lifted.
If the structure is to be raised, pumping continues until the soil reaches the point of compaction and begins to heave. Because the grout bulb is placed beneath and some distance away from the foundation, its effect on the foundation is indirect. The displaced, compacted soil is in direct contact with the foundation and uniformly raises it in a controlled manner.
WHY IT'S IMPORTANT
Foundations are designed to be fully supported by soil. Compaction grouting restores complete and uniform contact between the foundation and its supporting soil, as it was intended without changing the design function of the foundation.
Jacking a structure with pilings or piers causes point loading on the foundation, a condition for which it was neither intended nor designed.
COMPACTION GROUTING ADVANTAGES
- Address the causes of your settlement problems, not just the symptoms
- No excavation needed with compaction grouting
- Minimal disruption and project duration
- Not necessary to remove portions of the foundation, footings, driveway, sidewalks, patios, decks or landscaping
- Compaction grouting stabilizes and supports foundation uniformly by maintain or reestablishing complete contact between the foundation and the supporting soil beneath to allow the foundation to function as it was designed
- Process does not compromise unaddressed portions of the foundation
- Grouting equipment is left curbside, not on your lawn or driveway, eliminating the need for messy cleanups
- Repairs are undetectable upon completion
- Low cost - less expensive than jacking piers or piles
- Advantage over underpinning techniques – not requiring a rigid connection between the structure’s foundation and the underpinning element