Validating and Improving Models for Vibratory Installation of Steel Sheet Piles with Field Observations

Abstract

Vibratory driving is the most common installation technique for steel sheet pile walls. In practice, the assessment of the feasibility of this installation process is mainly based on rules of thumb, on numerical and empirical models or on experts opinions. In order to improve these prediction methods and formulas, 252 observations from the Dutch engineering practice have been compared with six different types of models. This comparison has been carried out applying the receiver operating characteristic (ROC) curve technique, which is new in geotechnical engineering. This paper introduces the ROC-curve technique to estimate mainly the quality of a model and to be able to optimize parameters and variables in the model. 252 field observations were used to re-examine prediction methods for the minimum required vibration force and to prove the ROC method works. The paper shows this technique is suitable for three purposes: (1) determining the quality of a model, (2) objectively comparing several models to each other, given certain assumptions and (3) for optimizing thresholds within a model. The model with added professionals’ experience proves to perform equally well as the numerical model Hypervib-I.