Lateral Load Carrying Capacity Of Helical Piles In Sand

Abstract

In the present study, an attempt is made to evaluate the lateral load carrying capacity of helical pile with varying embedment length and by varying relative density of sand. A series of model tests were conducted on pile with zero, one, two and three helices, with varying embedment depth of 700mm, 600mm and 450mm. The diameter of the shaft and helix is 30mm and 90mm respectively, the spacing of helices is one times the diameter of the helix i.e., 90mm. The pile is driven in both, loose state of sand (relative density = 35%) and medium dense sand (relative density = 50%).The ultimate lateral load increases as the embedment depth increases. The ultimate lateral load increases as L/d ratio (Where L=depth of embedment, d=diameter of shaft;) increases and also increases as the number of helices increases. The ultimate lateral load is more in the helical pile compare to plain vertical pile. The triple helical pile for all the embedment length offer more resistance and carry more load and higher resistance and least load is seen in the plain vertical pile. The ultimate load for all the embedment depth in medium dense sand was found to be more in all cases, than piles driven in loose sand. The increase in lateral load resistance with increase in embedment depth is attributed to increase in passive resistance. A Comparison was made between plain vertical pile and with varying number of helices in a helical pile with varying embedment depth. It was found that the lateral resistance increases even with increase of one helical and it is more as the number of helices increases. Also as the relative density of sand is increased, the lateral resistance was found to increase.