Addressing the SR 91 Freeway Settlement Issues
SR 91 is a highly trafficked freeway that serves the Inland Empire, connecting the Beach Cities on the West Coast to Riverside County in California. After a previous project was completed on the freeway, there was a significant issue with excessive settling in a specific section, evident from noticeable distress to retaining walls and facades.
Malcolm Drilling was contracted to mitigate these settlements underneath the freeway embankment induced by hydro-consolidation of the foundation soils. They assisted with the design and installed a compaction grouting scheme to mitigate the embankment settlement. A total of 750 columns were drilled in several grout arrays and variable inclinations, with lengths of up to 63 feet.
Malcolm proposed the compaction grouting program from the embankment wall toe instead of from the freeway pavement, avoiding frequent freeway shutdowns.