A field investigation was conducted to document the distributionof lime and fly ash (l/fa) seams and the resultant shear strength of an earth structure stabilized by l/fa slurry injection. The rehabilitation of the lower chariton river levee unit l-246 in dalton, missouri, was selected as the test site for this study. The study involved 56 hand vane shear tests and the mapping of l/fa seam coverage on 20 sample areas in seven test pits. Nine laboratory direct shear tests were conducted on undisturbed block samples from both treated and untreated areas. The results of unconfined compression tests performed by the u.S. Army corps of engineers, kansas city district, arealso described. The l/fa distribution pattern and surface coverage evaluation revealed that, on the average 1.6% Of the natural soil surface area is composed of l/fa seams. Based on an analysis of the strength tests reported, it appears that the double injection of the l/fa slurry in the levee increased the overall average strength of the soil by 15 to 30%, depending on the measure of coparison. In evaluating the long-term effectiveness of this stabilization technique, it should not be anticipated that the volume change potential of natural soil untouched by the injected slurry will have been changed. However, the crack filling and mending and the improvement in overallaverage shear strength suggest that l/fa injections are an appropriate and economical technique for maintaining slope integrity. This paper appears in transportation research record no. 1310, Construction innovations 1991.
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