دانلود رایگان مقاله انگلیسی نگرشی از تمرین پیش بینی بار نشست و فونداسیون سطحی - الزویر 2018

abstract

This paper describes an international exercise aimed at assessing the geotechnical engineering profession’s ability to predict the response of shallow foundations on soft clay subjected to undrained loading. Predictions of bearing capacity varied by more than an order of magnitude and settlement by more than two orders of magnitude. Average and median predicted values deviated significantly from measured values. The results of this exercise highlight the need to develop tools to assist engineers to process site investigation data. The development of predictive models that connect directly to site investigation data is discussed.

5. Concluding remarks

The results from the prediction exercise presented in this paper indicate that engineers with the same data and calculation task judge the data in different ways and ultimately produce very different results. Similar findings have previously been presented for prediction exercises involving shallow foundations on soft clay [21] and for the drained response of shallow foundations on sand [22,23]. This suggests that predictive capabilities have not improved, despite significant progress in modelling and testing techniques in recent years. It was demonstrated that reasonably accurate foundation performance predictions can be achieved using simple foundation models with parameters derived from the in situ and laboratory data provided. Therefore, the poor predictions cannot be attributed to insufficient or inaccurate information. No clear trends could be identified between methods used and the accuracy of predictions for either bearing capacity or settlement. The accuracy appeared to be entirely a function of the assumptions made regarding the boundary conditions, how model results were interpreted and, in particular, how soil parameters were selected. The accuracy of predictions was not strongly correlated to the sector of the predictor (i.e. practioner, academic or student). The range in the predicted values for both settlement and bearing capacity is undeniably alarming, with settlements varying by more than two orders of magnitude and the bearing capacity by more than one order of magnitude.