Site-Specific Risk Assessment of Sulfate Induced Heave in Lime-Stabilized Clay Soils

Practicing engineers are at times required to ameliorate or stabilize sulfate-bearing soils that exhibit sulfate-induced heave when treated with lime. Cost effectiveness of stabilization and amelioration techniques can be improved by using geologic models that identify the factors and processes that control the distribution of sulfate through the landscape. The paper describes the use of geospatial data sets, direct measurements of soil conductivity, and geochemical modeling to develop a geologic model of sulfate distribution along the SH-130 corridor in Texas. These geologic models can effectively be used to define the risk associated with sulfate-induced heave in soils that are encountered during construction. The technique can also be used to focus sampling and testing to the high-risk locations and thereby contributing to the economic success of the project. The sensitivity of soils to form ettringite/thaumasite with increasing sulfate concentration can also be evaluated using these geologic models.