Discussion. Settlement of Foundations on Sand and Gravel.

Abstract

The Paper was first presented in 1984 at the Centenary Celebrations of the Glasgow and West of Scotland Association and was published in the centenary volume. The paper is based on Mr Burbidge's Masters thesis' in which he assembled an enormous number of case records, each of them meticulously presented and analysed.122. As mentioned in 116 no attempt was made to compare the results of the correlations derived in the Paper with predictions of other methods as this would have required a case-by-case comparison. One of my students carried out comparisons of nine of the case histories for which the soils data were well established (Maail 1985).90 The observed settlements p, were compared with the calculated settlements p, using six methods including the one given in the Paper. The results are given in Fig. 34 where the observed settlements are plotted against pJp, and pJp, for each method. A point lying above the horizontal axis represents an overestimate of settlement (conservative) whereas a point lying below the axis represents an underestimate of settlement (unconservative). The number against each point refers to the case number given in Appendix-1.123. The predictions given by Terzaghi and Peck7 are given in Fig. 34(a) and can be seen to be generally very conservative. Meyerh~f'.'~ increased the allowable bearing pressure given by Terzaghi and Peck by 50% and dispensed with the correction for the water table. As can be seen from Fig. 34(b) some of the predictions have become very unconservative. Peck, Hanson and Thornburn (1974) proposed a revised set of charts with an overburden correction applied to the SPT results.'' Tomlinson*' uses the original Terzaghi and Peck charts with an overburden correction applied to the SPT results. These two methods give results which are plotted in Figs 34(c) and (d) respectively. It can be seen that in both cases the agreement between observed and calculated settlements is reasonable. Fig. 34(e) shows the comparison with Parry's method.33 For most of the cases the calculations are unconservative. As a check Fig. 34(f) shows the comparison with the method proposed in the Paper. It is encouraging that most of the observations lie within one standard deviation of the best estimate of the settlement. Mr E. J. Wilson, Consultant Engineering GeologistThe Terzaghi and Peck7 chart for estimating settlement is arguably the most used and almost certainly the most misused chart in soil mechanics; but it was produced in 1948 by Terzaghi and Peck on the basis of a study of plate bearing tests, some standard and non-standard penetration tests, and probably no actual settlement measurements on structures. They made it clear that this was a very conser-

A Comparative Study of Soft Computing Models for Prediction of Permeability Coefficient of Soil

“…ere are several direct relationships between grain size and the permeability coefficient of soil. Hazen [6] indicated that the permeability is proportional to the square of the effective grain size for the sand with uniform particles. Other authors proposed a regression that considers porosity, percentage of clay, and sand particle to estimate the permeability of soil [7].…”

Hybrid Model: Teaching Learning-Based Optimization of Artificial Neural Network (TLBO-ANN) for the Prediction of Soil Permeability Coefficient

“…e k-value is affected by many factors such as porosity, particle composition, mineral composition, and physical and mechanical parameters [1,2,4,[28][29][30]. However, this study will focus on the key factors that significantly influence soil permeability to reduce the complexity of the model.…”

The Appraisal of Hybrid Foundations on Loose Granular Soil of Western Saudi Arabia

“…The structure supporting soil mainly comprises sand with varying degrees of relative density [3]. Foundation settlement in loose sand is a universal phenomenon [4]. During the service life of a structure, foundations supported on sands, which have lower relative density may experience large settlements due to their low shear strength and high compressibility [5].…”