Significant Project Features:

• Implementation of 3 mix designs during Field Pilot Study.
• In-situ solidification (ISS) of approximately 5,082 cy of soil for landslide mitigation.
• 65 columns installed using Portland cement reagent addition for soil stabilization.
• Utilization of two mix designs during production drilling dependent on clay content of soils.

Project Background:

The Project Site is located about 10 miles east of Cuba, New Mexico, along New Mexico State Highway 126 in Sandoval County. Embankment failure has occurred between Mileposts 9.5 and 10.1.  Past efforts by others to address the issue using pumice fill were not successful.  Shear panels comprised of overlapping ISS columns were selected as the embankment mitigation method.

Description of Work

• Installed three ISS columns for Field Pilot Test program to evaluate three different mix designs.
• Installed 5 overlapping 9-foot diameter columns at each of the 13 shear panels, for a total of 65 ISS columns.
• Implemented two mix designs during production, increasing the W:C ratio of the second mix to produce a more fluid mixture.
• Maximum mix depth from ground surface ranged from 18.3 to 40.9 feet.
• Work was conducted between July and October 2024.

Key Project Objectives

• Install overlapping ISS columns within each shear panel such that treatment area replacement ratio is at least 22% and the columns extended into bedrock.
• Ensure that the strength of the soil-cement stabilized columns is greater than the required design strength of 75 psi.
• Verify through coring of select columns that the soil-cement material is uniformly mixed with no voids or untreated areas over the full depth of the column.

Project Challenges

• Limited work space for equipment. Working within a closed-off lane adjacent to a controlled-access traffic lane on one side and a steep slope on the other side.
• Difficult subsurface drilling conditions due to boulder obstructions and old fill material.
• No internet/phone service due to remote location.
• Equipment breakdown issues partially due to subsurface conditions.
• Difficulties conducting verification coring of ISS columns without the use of water due to the high amount of clay and the low required compressive strength of the soil-cement stabilized material. Could not use water to assist coring efforts without washing away the core material.