_GENERAL DOCUMENTS - C1981017 ‎(218)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

-2-
My supplemental memo of July 12, 1984 presented an additional concern
requiring resolution by the applicant;
(4) Because of the extremely low observed permeability of the
alluvial/colluvial materials, which will comprise a significant portion
of the immediate foundational materials beneath the proposed pile, the
Division is concerned that loading rates might exceed the consolidation
settlement capability of that foundational material , which could result
in a foundational failure. Specifically, our concern is that an
undrained failure of the foundational material might occur due to
loading rates exceeding the materials capability to drain pore fluids
and consolidate during the construction (short-term) of the pile. The
analyses performed and included within the amended application assume
both saturated drained (long-term) conditions and worst case total
stress (short-term) conditions.
The applicant had not performed effective stress triaxial testing
sufficient to provide the parameters necessary to complete the
derivation of undrained effective stress shear strength parameters for
the foundational colluvium beneath the proposed pile site. However, as
an alternative, the applicant's consultant performed a stability
analysis based on worst case total stress parameters, i .e. assuming
instantaneous application of a vertical load equivalent to that of the
ultimate 5-year waste pile configuration. Utilizing these worst case
assumptions the analysis projects a worst case static slope safety
factor of 1.6 and a worst case pseudo-static slope safety factor of
1 .35 for the proposed pile. The applicant has demonstrated, to the
Division' s satisfaction, that the proposed waste pile's foundation will
provide adequate support underdrealistic anticipated rates of loading.
/ep
cc: Brian Munson
Doc. No. 3459