The Remediation of Hotel built on Top of a Landfill - Part I
We have another project (similar to the last tilt up Phoenix warehouse project) that is challenging our technical experts to utilize every creative tool in our toolbox to accomplish the customer’s goals.
This hotel was built on top of a trash landfill with 10 feet of compacted fill on top. The landfill differed from the last project, in its variety of its fill. In addition to concrete, steel (car parts) it included trash with its decay produced methane and hydrogen sulfide. These difficulties restricted our drilling capacities. Injecting fresh oxygen down to these explosive gases with a down in the hole hammer is not a prudent solution.
This foundation repair project becomes a challenge when transitioning to the inside where our large excavators will not fit.
Above are some of the signs of stress that were discovered to indicate the movement of the structure as a result of soil movement below.
In addition to the explosive potential, these gases also present breathing health hazards to our crews working on site. In response, we hired an industrial environmental engineer to insure working site safety conditions. Among other things, we equipped each worker with gas sensors and emergency oxygen.
Compaction grouting was chosen as the preferred method to stabilize and re-level the foundation. The casing was simply hammered down with a large hydraulic concrete hammer with a custom fabricated transition piece between the hammer tip and the casing to protect it from the percussive blows of the hammer. In addition, a sonic boring was done to verify the strata at the hammered depth of 50 feet.
Compaction grouting was chosen as the preferred method to stabilize and re-level the foundation.
This foundation repair project becomes a challenge when transitioning to the inside where our large excavators will not fit. Sonic drill rigs will not fit into the workspace, either. For the time being, we are left using smaller excavators, with smaller hydraulic hammers.
At first, we simply utilized a compact mini loader to load the sand and aggregates to the mixing hopper mounted to the machine. However, in later portions we would need to find a more compact solution that has less of an area to shut down… more on that to come!
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