Screw pile in alluvial soils - driving torque uplift capacity and soil strength relations

Abstract

The available soil and uplift load test data for the screw pile used in the foundations of towers for East-West Electrical Interconnector Project (Pabna region) were analysed in order to find some relationship between soil strength and driving torque and also between uplift load and displacement. Mathematical models were developed by using simplified assumptions to correlate soil strength with driving torque and uplift load with displacement of screw piles. The statistical analysis of the data against these models v showed that a good correlation exists between driving torque and soil strength for the screw piles of this area. Model was also developed for the uplift load-displacement behaviour of the screw'piles and the statistical analysis showed that there exists a strong relationship between the ratios of applied load/ultimate capacity and displacement/embedment length. The relationship is loglinear and can be used to predict the uplift displacement of screw piles from the driving test results.