The ground properties given in the exam tend to be stated in terms of SPT 'N'.
SPT stands for Standard Penetration Test, a simple and widely used method of ground investigation. The test is carried out by sinking a sampler inside a borehole and striking it repeatedly with a "hammer" of known weight dropped a known height. The number of blows required to progress the sampler 300mm through the strata is known as the SPT 'N' value and can be correlated with ground properties.
This cheat sheet is based on BS8004, which is non-contradictory complimentary information to Eurocode 7. The method set out calculates a pile resistance directly from the SPT 'N' value, without the intermediate step of correlating SPT 'N' with ground properties.
The calculations apply both a partial factor (2.0 for base resistance and 1.6 for shaft resistance) and an additional "correlation factor" based on the number of samples taken (the more samples taken, the smaller the partial factor due to reduced uncertainty). If you assume the SPT 'N' given was calculated from a single test result, then this correlation factor is 1.55, giving a combined factor of safety of 3.1 on the base resistance and 2.5 on the shaft resistance (surprise surprise, the factor of safety on the geotechnical design is ~3).
The cheat sheet presents pre-calculated values for the empirical coefficients you will need to calculate the skin friction and end bearing resistance of the pile.
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