A METHOD FOR ESTIMATION OF GROUND LAYERED SYSTEMS FOR THE CONTROL OF STEEL PIPE PILE GROUP DRIVING

A new method for the estimation of ground layered systems, which is to suggest the dynamic design method of steel pipe pile groups, is proposed, in a probabilistic manner. The distinctive features of the method are as follows: (1) The method is safer and easier than other methods, as it needs only a general soil boring investigation prior to, and measurement of blow count data during, the pile driving. (2) Not only is the pile bearing capacity estimated, but the accuracy of the estimation can be evaluated. (3) Attention is given to the regulation of sedimentation layers from the geological point of view. (4) It can make a higher accurate estimation than a current design method. Real ground layered systems are estimated by the method, and it becomes clear that the variation of pile bearing capacities, and of the uncertainty of these, cannot be ignored even within one site. A chart, to use the arrangement of the variations, is also provided. Its applicability is examined by real pile driving data, and it becomes clear, that the effect of the magnitude of bearing capacity, and also the accuracy of the estimation to the design alteration, is well presented in the chart.