Effects of Frost Heave on a Soil Nail Wall in Brunswick, Maine

Soil nail walls have been used as retaining structures worldwide since the early 1970s. The technology is particularly well suited for constructing walls in areas with limited overhead clearance and maneuvering room for heavy equipment, such as highway bridge underpasses. However, designers have been reluctant to experiment with soil nailing in areas with cold-weather climates and frost-susceptible soils, due to the lack of quantifiable data on the behavior of these walls when subjected to freezing conditions. The University of Maine collaborated with the Maine Department of Transportation (MDOT) in a research initiative on the first soil nail wall project in Maine, constructed along Route 1 as part of the Brunswick-Topsharn Bypass Project. Selected components of the wall were instrumented to determine what effects the freezing winter temperatures would have on the wall and surrounding soil. Instrumentation included strain gages, load cells, a total pressure cell, thermocouples, and survey points. Despite a transient peak tensile stress exceeding the desired factor of safety of three in one of the PIP- = nails during the coldest period of the study, analysis of the instrumentation data indicated that the wall was not significantly affected by freezing temperatures during the wall\u27s first post-construction winter season. The findings from this undertaking directly influenced MDOT\u27s planning process for a larger and more extensively monitored soil nail wall on Route 201 in Moscow, Maine, and contributed to the limited existing compendium of knowledge concerning the behavior of soil nail walls under cold weather conditions

Advisory Committee:

Soil nail walls have been used as retaining structures worldwide since the early 1970s. The technology is particularly well suited for constructing walls in areas with limited overhead clearance and maneuvering room for heavy equipment, such as highway bridge underpasses. However, designers have been reluctant to experiment with soil nailing in areas with cold-weather climates and frost-susceptible soils, due to the lack of quantifiable data on the behavior of these walls when subjected to freezing conditions. The University of Maine collaborated with the Maine Department of Transportation (MDOT) in a research initiative on the first soil nail wall project in Maine