Project

The project consisted of upgrading the intersection of Interstate 10 at the Avalon Blvd (SR 281) interchange in Milton. The upgrades included several embankments and MSE walls associated with new on and off-ramps with fill heights up to 10 feet.

The Problem

The geotechnical investigation revealed a soft clay layer of variable thickness ranging from three to twenty feet thick. This clay layer would consolidate over time, causing excessive total and differential settlement, leading to detrimental damage to the proposed roadway. The soft clay layer also created slope stability issues.

Earth Tech Solution

Earth Tech’s ground improvement solution consisted of Low Mobility Grout Rigid Inclusions (LMGRI’s) to provide support for the embankments and MSE walls. Earth Tech designed and installed LMGRI’s that transferred the embankment loads through the soft clay layer encountered at varying depths. LMGRI’s were installed on a uniform grid pattern across and beyond the embankment areas to depths of approximately thirty to seventy-five feet below grade. LMGRI’s were extended beyond embankment areas to provide additional reinforcement against a slope stability failure.  Soils overlying the soft clay consisted of dense sands and were utilized as a load transfer platform.