PERMFILE108040

• Permit No: C1981019
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: Sections 10 - 16
• Section_Exhibit Name: Exhibit 12 Experimental Part 3
• Media Type: D
• Archive: No

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develops. The analysis .conditions and results are presented on Fig. 10. We
also analyzed reduced strength conditions assuming the perched water degrades
the spoil and reduces the strength considerably. Under these conditions,
with a high water table and a lowerbound strength of ~=10 degrees and C=200
psf, the factor of safety was found to be approximately 1.05.
DISCUSSION
Slope failures can be considered either deep-seated or shallow. Minor
slumps or slides belong to the shallow category and while a nuisance, seldom
cause economic disaster or loss of life. Because of the importance of deep-
seated failures, a large amount of effort was expended analyzing this type
of failure. As shown on Fig. 4, critical circles C-1, C-2 and C-3 apply to
• three classes of deep-seated failure. Circle C-1 illustrated a failure con-
fined within the spoil. Circles C-2 and C-3 analyze conditions where the
failure surface is confined within the alluvium and bedrock, respectively.
Circle C-3 provides a very unlikely condition due to the relative hardness
of the bedrock and depth to which the circle penetrates. Failure circles with-
in the colluvium should also be somewhat unlikely because of the consolidation
and strength gain provided by placement of the spoil. For analysis, we used
conservative values for the colluvium strength and, in general, found factors
of safety higher than circles confined to the spoil.
The results of shallow seated failure analysis suggests a possible failure
condition could occur under high water table conditions at the toe of the slope.
It should be noted that previous analyses indicated identical results and the
• failures are attributed to high water, not the presence of additional spoil.