A subsurface investigation in Taylor clay
A comprehensive field and laboratory investigation at the location of the Lymon C. Reese Research Wall is presented. Soil at the site is a stiff, fissured and heavily overconsolidated clay from the Taylor Group. Index properties such as Atterberg limits and clay fractions were used with common empirical guidelines to assess the qualitative swell potential. The soil's compressibility and strength characteristics were difficult to measure in the lab, owing to the stiff soil's secondary structure. Measured values were compared to well established correlations and test results from similar soils sampled from locations near the present test site. Cyclic swell tests were to predict the soil's lateral swell potential after multiple cycles of wetting and drying. Empirical guidelines indicated the soil has a "high" to "very high" swell potential. This was validated by the swelling that was observed during consolidation and cyclic swell tests. The soil's drained and undrained strengths were both rather large, often more typical of rock than soil. The stress history was not evident from consolidation results, either due to disturbance, cementation or extreme overconsolidation. The hydraulic conductivity was particularly elusive, again due to the soil's secondary structure.