<p><p><div><img class="wp-image-3353 size-full aligncenter" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Diagram of bulk infill grouting along Interstate 70 in Guernsey County, Ohio." width="360" height="298" /></div><h2>Project Summary/Scope:</h2><div></p><p>A 13 feet (4 m) by 10 feet (3 m) deep subsidence suddenly developed in the east bound lane of Interstate 70 in Ohio as a result of an underlying mine working. The road needed to be closed for more than 3 months while a grouting remediation program was performed. The length of the project was 2000 linear feet.</p><p>Subsurface Conditions: Mined out voids existed at a depth of approximately 66 feet (20 m) below ground surface.</p><p>High volume grouting using a flyash grout was specified to completely fill all subsurface mine voids.</p><p>Approximately 1,800 boreholes were drilled down to the mined coal seam using air rotary drilling. Air rotary drilling of grout placement holes sometimes forced water from water-filled abandoned mines out of nearby holes. Approximately 18,000 CY (13,800 m³) of grout was pumped into the subsurface voids. Two land bridges with lengths of 700 feet (213 m) and 110 feet (34 m) were constructed over areas where the drilling encountered high concentrations of caved and broken materials at the mined level.</p><p>The project lasted from March 1995 to July 1995.</p><p><figure id='attachment_3354' style='max-width:461px' class='caption aligncenter'><img class="wp-image-3354" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of water forced out of a water-filled abandoned mine as the result of bulk infill grouting." width="461" height="303" /><figcaption class='caption-text'> Air rotary drilling of grout placement holes at I-70 in Guernsey County sometimes forced water from water-filled abandoned mines out of nearby holes.</figcaption></figure><h2>Cost Information:</h2>The total cost of the project, including land bridges and pavement replacement, was $3.6 million.<br><h2>Project Technical Paper:</h2>Ruegsegger, L.R. and Lefchik, T.E. (1999). “Managing Car-Crunching Sinkholes.” Public Roads, 63(1).<br><h2>Date Case History Prepared:</h2><strong> </strong>November 2012</p><p></div></p></p>