<p><p><h2>Project Summary/Scope:</h2>The rehabilitation of a historic structural fill embankment along Trail Ridge Road in the Rocky Mountain National Park near Estes Park, Colorado was completed using compaction grouting. Cracking of the pavement section was observed, and settlements of 100 mm/year were measured. The settlements were attributed to piping around a nearby culvert. The embankment was 20 meters high and 40 meters long with a slope of 1.25H:1V.<br><div>Subsurface Conditions: The slope consisted of a rock fill with many voids in the rocks near the top of the slope.</div><div></div><div>Four longitudinal lines of grout holes were designed at a spacing of 2 meters apart across the roadway width and 4 meters apart along each line. The lines were staggered 2 meters to create a triangular pattern. The grout holes were to be terminated upon reaching bedrock. Stopping criteria were established at 1,400 kPa, 20 mm/meter horizontal displacement of guard wall, 40 mm/meter horizontal displacement of the armored rock face, a volume of 0.25 m³/300 mm, or an upward heave of the ground surface in excess of 100 mm.</div><div>The culvert was lined to prevent further piping. The voids in the rock armored slope were filled with grout to stabilize them. Compaction grouting was used to densify the fill and was implemented from depths between 2 and 9 meters to the depth of bedrock. The stages of compaction grout were every 300 mm. QC/QA Methods: Typical grout volume, pressure, and heave criteria were used. In addition to these methods, the results were verified using the seismic method known as High Definition Imaging (HDI). Seismic data was taken through the use of geophones at the ground surface.</div><h2>Performance Monitoring:</h2><div>Grout effectiveness was assessed by looking at the grout volume and pressure takes. The seismic data collected showed an increase in the relative shear wave velocities in the area near the grout injections.</div><h2>Project Technical Paper:</h2><div>Haramay K.Y., Henwood, J.T. and Szynakiewicz, T. (2009). “Assessing the Effectiveness of Compaction Grouting Using Seismic Methods,” Contemporary Topics in Ground Modification, Problem Soils, and Geo-Support, ASCE, GSP 187, pp. 241-248.</div><h2>Date Case History Prepared:</h2><div>November 2012</div></p></p>