Hillsborough County Florida is using a mix of expanding polyurethane foam and conventional cement grout as a more cost effective means of filling sinkholes. Officials say the mix uses 30 to 40% less grout adding up to a 30% cost savings. The article in the Tampa Tribune did not indicate the contractor or product name that they are using but apparently several agencies in California and other states are using the same material. Story via ASCE SmartBrief.
Geologic Hazards
40 Foot Sinkhole in Tenn. Stadium Endzone
A large 40 foot wide by 40 foot deep sinkhole opened up just outside the endzone of Austin Peay State University’s Governors Stadium in Tennessee. The stadium is currently undergoing upgrades for next year’s football season. Sinkholes are not unexpected on Austin Peay campus, and the video below shows one example of how the University has actually incorporated the remediated sinkholes into the landscaping. Representatives from the University and the contractor expect the sinkhole will be filled without any problems.
[Updated 1/19/2015] Click through for the video since I can’t figure out how to turn off the auto-play on this one. [/Updated]
Geologic Hazards
Maitland Sinkhole Stabilization Project – Central Florida
A massive sinkhole more than 300-ft in diameter and with depths to bedrock of up to 350-ft is located under a future I-4 traffic interchange in an Orlando suburb. A massive $9 million stabilization project is underway to prepare the site for the eventual TI construction. The size of the Maitland Sinkhole is on par with the largest sinkholes to form in central Florida in recent times. There is not a void present, instead it is infilled with a compressible sand deposit. (Image from FDOT)
The mitigation method includes drilling over 300 grout injection holes, and performing grouting operations to infill cracks in the limestone bedrock. Then in the same holes, compaction grouting will be used as a method of ground improvement to densify the sand in place. Once the grouting is complete, the site will be surcharged to compress any remaining weak layers. Click through for a subsurface profile and location map. Via ASCE SmartBrief.
News
Video: Port of Los Angeles Seawall Stabilization Project
This is a great application of polyurethane grouting, to fill voids and stabilize soil behind a seawall at the Port of Los Angeles. Check out the video below from EagleLIFT.