Pile-settlement evaluation using field stiffness non-linearity

Understanding the principal features of soil stiffness has been one of the major achievements of geotechnical engineering over the past 30 years. The study of modulus degradation is now one of the main research areas. Understanding non-linearity is essential in foundation design for accurate and reliable evaluation of ground movements. This paper looks at the problem of assessing of deep foundation settlements and describes two approaches developed to enable designers to take soil–foundation non-linear behaviour into account. The first provides in-field stiffness parameters evaluated by back-analysis of full-scale piles. The second involves deducting the behaviour of the soil interacting with a foundation from degradation curves characterising the soil stiffness.