UFC 4-151-10
10 September 2001
6-2.7
Change in Loading. In some cases, the design load represents a
temporary or construction condition, and the service loads are of lesser severity. For
example, if a retaining wall is well drained, maximum lateral pressure will occur during
and shortly after back-filling, dissipating somewhat with time. Another example is that of
a hydraulic fill. The lateral pressure decreases as the fill drains. Borings will help in
evaluating actual, in-place soil properties at the time that evaluation is made.
6-3
EVALUATING CONCRETE STRENGTH USING LOAD TESTS
6-3.1
described in paragraphs 6-3.2 through 6-3.4.
6-3.2
reduced load (for tributary area). This increased loading intensity will require careful
observation and control to preclude precipitating collapse. For this purpose, load in six
increments, rather than four, and where feasible, use water-loading for safe provision of
emergency drainage and load removal.
6-3.3
Lateral Loads. Simulate lateral loads expected to occur simultaneously
with vertical loads in the test.
6-3.4
Loaded Area. Make the loaded area large enough to ensure that
additional strength due to continuity and three-dimensional action within the structure is
properly reflected in the test.
6-4
SPECIAL PROVISIONS REGARDING CAPACITY OF EXISTING PILES
6-4.1
Structural Capacity. Check existing piles checked for effects of
deterioration. A reconnaissance survey should be made to identify areas of "worst
conditions." Measurement of overall residual strength in 1 percent to 2 percent (but not
less than 4) of the piles will be considered an adequate statistical sample on which to
base judgment of capacity. Use the "worst" piles of the group as identified in the
reconnaissance survey.
Give consideration to probable, future progression of loss of strength.
Usually, the mudline under a platform has accreted well above the normal, stable slope
line drawn from the existing dredge level alongside the platform. Discount this material in
estimating the un-braced pile length (L). Should future dredging to greater depth be
contemplated, consider the increased un-braced pile length that would result.
6-4.2
Capacity of the Soil to Support the Pile. Unless the embedded length of
a pile has been reduced by scour or dredging, assume no reduction in bearing capacity
from that initially achieved during driving. Where installed capacity is not known, consider
the use of load tests to establish capacity.
6-3
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