Low mobility grouting, or LMG, is used in very specific situations where the grout that is mixed has a limited ability to travel to its injection point. This is the case in karst solution cavities. These are cavities created by water erosion of soluble rock. Since much of Florida topography consists of limestone, karst cavities are common. These are dangerous formations that can become sinkholes if not repaired. Our area, being a location with a high water table, is prime for voids in the earth. For your sinkhole repair solutions, contact the low mobility grouting Florida experts – Foundation Professionals of Florida.
Low mobility grouting, also known as compaction grouting, is a grouting technique that displaces and compacts loose granular soils. It also reinforces fine-grained soils and stabilizes subsurface voids or sinkholes by the staged injection of low-slump and low mobility aggregate grout.
Low mobility grouting was developed in the 1950s as a remedial measure for the correction of building settlement and used almost exclusively for that purpose for many years. Over the past 25 years, however, low mobility grouting technology has evolved to treat a wide range of subsurface conditions for new and remedial construction. These include rubble fills, poorly placed fills, loosened or collapsible soils, sinkhole sites, and liquefiable soils.
Typically, an injection pipe is first advanced to the maximum treatment depth. The low mobility grout is then injected as the pipe is slowly extracted in lifts, creating a column of overlapping grout bulbs. The expansion of the low mobility grout bulbs displaces surrounding soils. When performed in granular soil, low mobility grouting increases the surrounding soils density, friction angle, and stiffness. In all soils, the high modulus grout column reinforces the soils within the treatment zone. By sequencing the low mobility grouting work from primary to secondary to tertiary locations, the densification process can be performed to achieve significant improvement. Low mobility grouting has been used to increase bearing capacity, and decrease settlement and liquefaction potential for planned and existing structures. In karst geologies, low mobility grouting has been used to treat existing sinkholes or to reduce the sinkhole potential in sinkhole-prone areas.
As far as the method of injection is concerned, low mobility grouting is performed in a way very simulator to compaction grouting. The major difference is the slump range of the grout mixture. Injection rates need to be increased as well, due to the voids versus soil displacement ratio. This allows for pore pressure dissipation, and the possibility of other time-related issues. LMG rarely causes major disturbance at a job site, can improve deep foundation systems, can be used to level surfaces, and can increase soil density so it is a very useful tool.
Low mobility grouting offers an economic advantage over conventional approaches such as removal and replacement, or piling, and can be accomplished where access is difficult and space is limited. Compaction grouting for treatment beneath existing structures is often selected because the low mobility grout columns do not require structural connection to the foundations.
Low mobility grouting is a great way to improve the ground when there is a void. It takes a very special team like the team at Foundation Professionals of Florida to handle this type of grouting. Since LMG is only for certain special situations you will definitely want to have a structural engineering team make sure it is right for your application. We gladly provide estimates and will evaluate your site to make sure low mobility grouting is right for you. It might prevent you from having to do full-blown sinkhole repair later. Contact the professionals today, the Foundation Pros of Florida team. We service Lake City, Jacksonville, Tallahassee, and the surrounding areas.