Low Mobility Grout Rigid Inclusions

Low Mobility Grout Rigid Inclusions (LMGRI’s) are grout columns installed to transfer a foundation load to a competent soil or rock bearing stratum. LMGRI’s are constructed by drilling a grout pipe to the bearing stratum. The LMGRI Column is then constructed by withdrawing the grout pipe in intervals while injecting a known volume of grout to create a continuous column.

The LMGRI column is terminated within a few feet of the foundation.  In some applications the LMGRI column may terminate in a competent stratum located beneath the foundation.  In this instance, the LMGRI is transferring the load from a shallow competent stratum through a compressible stratum and ultimately taking up load in a deeper competent bearing stratum.  Unlike deep piling systems, LMGRIs are not constructed into a pile cap.   A Load Transfer Platform (LTP) system is designed and installed on top of the LMGRIs to transfer the load of the foundation.

Applications

  • LMGRI’s are used in soil profiles in variable soil profiles with compressible layers located between a competent surface layer and a bearing stratum
  • Low to mid rise new construction buildings

  • Area loads such as tanks and embankments

Construction Advantages

  • Economical compared to  deep foundations and does not require pile chipping, cut-off or cap

  • Increased allowable soil bearing capacity reduces the size of foundations

  • Expedient process
  • In the Tampa Bay area, Earth Tech can provide and deliver  grout from its ready-mix plant to maintain project schedule
  • Outside of the Tampa Bay area,  Earth Tech can  supplement third party grout deliveries with its own ready-mix trucks to maintain project schedule

What to expect

  • Earth Tech will provide a signed and sealed design indicating treatment plan and if needed Load transfer platform details.
  • Site clearing and access preparation precede LMGRI
  • Site access for ready- mix trucks is needed.
  • Drilling spoils may accumulate on the surface and must be disposed of
  • Typically, this work is performed under a performance specification, with criteria specified regarding bearing capacity and settlement
  • Load testing can be used to verify design criteria
  • A load transfer platform may be needed and is typically constructed by others.
  • Final site grading, spoil clean up and foundation construction follow the LMGRI’s.