Probabilistic Prediction of Maximum Tensile Loads in Soil Nails

Abstract EN

This paper presents the development of a simplified model for estimation of maximum nail loads during or at completion of construction of soil nail walls.

The developed simplified nail load model consists of two multiplicative components: the theoretical nail load and the correction factor.

The theoretical nail load is computed as the product of lateral active Earth pressure at nail depth and the nail tributary area.

The correction factor is introduced to account for the difference between the theoretical and the measured nail loads.

A total of 85 measured nail load data were collected from the literature; out of which, 74 were used to develop a simple formulation for the correction factor, whereas the remaining 11 were used for validation.

After the validation, the model was updated using all 85 data.

The updated simplified nail load model was demonstrated to be accurate on average (mean of model factor equal to 1), and the spread in prediction quantified as the coefficient of variation of the model factor was about 40%.

Here, model factor is the ratio of measured to estimated nail load.

The randomness of the model factor was also verified.

Finally, the model factor was demonstrated to be a lognormal random variable.

The proposed simplified nail load model is beneficial due to its simplicity and quantified model uncertainty; thus it is practically valuable to both direct reliability-based design and load and resistance factor design of soil nail wall internal limit states.