Challenge

LRE Commercial (LRE) was called to help with the settlement issues that the Plymouth at Amelia Apartment building was experiencing. The Northern portion of buildings exterior foundation was underpinned in the past. This work was preformed by another foundation contractor. the foundation had continued to settle over time and needed to be stabilized. Bechtol Engineering preformed 2) SPT borings and 9) shallow auger borings, November 2019. It was found that there was buried construction debris and possibly an old landfill below that end of the building.

Solution

LRE Commercial retained Ramos Engineering & Associates (RE&A) to formulate a stabilization program. Using Bechtol Engineering's preliminary information, RE&A recommended using drilled piers to drill through the buried debris and bear on component soil. LRE Installed 1 drilled piers to a depth of 200 feet, without reaching soil that would support the structure. To be able to support the structure without going so deep, RE&A switched the piers from Drilled to Helical style. The 40 kip ultimate capacity was achieved by using a 10" - 12" helix configuration, with cutting teeth at the pile tip and first auger flight, on a Foundation Supportworks, FSI 288 Shaft. The torque correlation method was used, to verify that the piers were installed to a minimum 4,450 ft/lbs of torque, to achieve the ultimate 40 kip compressive loading. The pier depths ranged from 26 to 72 foot depths. After the pier installation was completed, each pier was loaded to transfer the buildings load from the ground surface to the piers.

Project Summary

Geotechnical Engineer: Bechtol Engineering

Engineer of Record: RE&A

Certified Installer: LRE Commercial

Products Installed: 38) FSI 288 10" - 12" Helical Piers

Challenge

LRE Foundation Repair (LRE) installed exterior piers on the perimeter footer July 2020. The piers are preforming as designed with no new settlement to date. LRE was called, July of 2021 to help with the settlement issues of the interior slab at the Plymouth at Amelia Apartment building. The same Northern area of buildings interior slabs and partition walls in units 5 & 6 were settling. The slab and partition walls are independent of the exterior wall and foundation elements. The Apartment complex houses university students and the repair was required to be designed, permitted and completed, prior to start of the next school semester.

Solution

The owner retained Ramos Engineering & Associates (RE&A) to formulate a stabilization program. RE&A designed the interior slab and partition wall stabilization for units 5 & 6. The design included using, 31 Foundation Supportworks, FSI HP 287 piers, with 8"-10" helix configuration. The design included retro fit brackets for the interior load bearing walls and slab brackets for the slab areas. LRE successfully installed the piers in time for the apartments to be rented out for the upcoming school year.

Project Summary

Engineer of Record: RE&A

Certified Installer: LRE Commercial

Products Installed: 38) FSI 288 10" - 12" Helical Piers

Helical pier installation back of building

Helical pier installation front of building

Helical pier installation

Helical pier installation with small equipment

Helical pier installation with hand held equipment

helical pier and slab brackets installed