Sinkholes at the Dead Sea have threatened tourists and forced Israeli (and perhaps Jordanian)authorities to close various facilities and cancel development plans to avoid these geologic hazards. These are not your typical Karst sinkholes. According to a recent AP article, they are caused by the erosion of salt deposits by fresh water as a result of the lowering of the water level. This is a human caused phenomenon as current size of the Dead Sea is just 1/3 of its size in 1960 since water has been diverted from the Jordan River, its main tributary to be evaporated for its phosphates. At the end of the article is an interesting note that the World Bank is currently evaluating a proposal to replenish the Dead Sea by digging a $15 Billion canal from the Red Sea, about 100 miles away. (Photo by urban_hipster)
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.