Florida SR-66 Sinkhole Monitoring

Public Deposited

In early 2001, a sinkhole formed directly under State Road 66 near the city of Sebring in Highlands County, Florida. The Florida DOT built a land bridge over the sinkhole and the road was reopened to traffic. Since SR-66 is an important regional trucking route, it was decided that the site should be closely monitored for any future sinkhole growth. The geotechnical consulting firm GeoTDR, Inc. installed time-domain reflectometry (TDR) cables and biaxial tiltmeters at strategic locations. The instruments and communication equipment are powered by a solar panel and deepcycle battery. The communication link is powered on for only a brief window each day in order to save power. Since there is no telephone service at the site and cellular coverage is spotty, ITI engineers built a radio link system to connect the site to a modem on the nearest telephone pole, slightly over half a mile away. Two events lead to the April 2005 site visit. First, in March 2005, FDOT personnel monitoring the instruments via the Civil Data Systems web site noticed that one of the TDR cables appeared to have been sheared. In addition, a site visit revealed that several washouts had formed along the sides of the land bridge. Second, later in March, communication with the site was lost. A site visit by FDOT personnel revealed that the solar panel powering the instrument box had been sawn off its pole and stolen. ITI engineers decided to travel to the site to replace the solar panel and perform other maintenance tasks.

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  • 08/14/2017
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