Civil Engineering Reference
In-Depth Information
Table 9.3
Essential information to accompany pile test sheets
Item
Information needed
Dates
Date pile was installed.
Date of test.
Location
Sufficient detail to permit the site to be located and also the position of
the pile relative to the works. The pile number should always be
stated.
Pile type
Various categories of pile type are set out in Weltman and Little (1977)
(undergoing revision).
Pile installation details
If a bored pile (i.e. non-displacement), the depth of temporary casing,
how much concrete, mix details, how placed (e.g. trémie or chute
into dry bore), and any special circumstances, particularly regarding
groundwater. If driven (i.e. displacement), type of hammer, weight,
drop, final set. The driving record should accompany pile test report.
Pile dimensions
Nominal diameter (or section) weight per metre run as applicable. Size
of underream, bulb, 'wings', etc. Length of the pile - include the entire
pile length.
Installed level (driven)
Concreted level
(bored) Trimmed
level and toe level
Give full data so that there is no doubt regarding the reduced level of
pile toe, the ground level
at the time of the test
and the level of the top
of the pile either at the end of installation, after trimming or both
(above or below ground level).
Orientation
State whether vertical or raking (with degree of rake if applicable).
Design Load of pile
State Design Load or indicate on plot.
Type of test set-up
and settlement
measuring system
Whether kentledge or tension pile test. Leading plan dimensions of the
set-up including reference system. Method of measuring settlement,
subsidiary levelling of reference beams, temperature corrections.
Weather
Brief comment on weather conditions and extremes of temperature
during test.
Soil information
It is not generally feasible to provide full soil information. If a report
exists, the name of the company who produced the report should be
given, together with a reference number. The position of relevant site
investigation boreholes should be given on the pile location plan.
Summary logs of nearby boreholes with SPT
N
values and cohesion
values alongside are useful. In some cases, a Bored Piling Contractor
will log the boring - such logs should be given with an indication of
their source.
The
reduced levels
of boreholes must be given.
9.2.4 Interpretation of the results
A considerable amount of data may be computed from a pile test, and with more
sophisticated instrumentation a greater understanding of the pile-soil interaction may
be achieved. As discussed in section 9.1, it is important that the designer is satisfied
that the behaviour of an isolated test pile under relatively short-term loading stresses
the bearing stratum in a similar manner to the piles in the foundation. Interpretation
of the pile test data may be carried out on several levels:
1
qualitative inspection of the load settlement curves;
2
a check for compliance with load and deformation specifications; and
