07/1571 - Response to Information Request [As Published] · 142007.1571

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Project 306-2325

 

 

 

 

 

 

 

 

 

 

 

1. NR - Not Recommended; NC - Not Considered in skin friction calculations.

2. Higher design parameters may be adopted depending on final pile type. Recommended
geotechnical strength reduction factor (@,) = 0.45 to 0.55.

3. Considering limit state analysis (AS 2159-1995), the design geotechnical strength R*, is
calculated by multiplying: the. ultimate geotechnical strength Ru by the geotechnical strength
reduction factor @,, ie. R*y = Rug x By.

4. Should a "working stress" approach be adopted, a minimum factor of safety of 3.0 on base and
2.0 on skin friction is recommended.

 

 

 

Based on the range of values provided in AS2159-1995 it is recommended that the
geotechnical strength reduction value of 0.45 be adopted for the design of deep
foundations on this site in conjunction with the ultimate strength values provided in Table
4.

Depending on the load requirements, and the piling contractors design, it is
recommended that the piles are founded in material which is at least dense, and at a
minimum depth to meet the scour requirements.

6.3.4 Construction Considerations
inspections

It is recommended that inspections be undertaken by an experienced and qualified
geotechnical engineer following footing excavations to confirm the adequacy of the
founding soils. Inspections should be carried out prior to placement of reinforcing steel
and ordering of concrete.

 

Y SOIL SURVEYS ENGINEERING

February; 2006——_____—+ Tre memes Paget? =
TABLE 4 ULTIMATE GEOTECHNICAL STRENGTH PARAMETERS
Sand - Loose — NR NR
~ Medium Dense 1000 20
Clay - Stiff to Very Stiff 675 30
- Very stiff to Hard 1350 45
Sandstone - Extremely Weak 1800 60
- Very Weak to Weak 2200 75
Notes: :