In this paper, the vertical pullout behaviour of batter piles has been brought out. Batter anchor is an inclined pile subjected to vertical uplift force. An experimental work was carried out to study the behaviour of batter anchors using model aluminum pipe piles of 19 mm diameter embedded in soft marine clay bed prepared at different consistencies. Tests were conducted on piles with batter angles of 00, 100, 200 and 300. Further the effect of length of embedment on the uplift capacities of batter anchors was brought out. These experimental investigations were carried out in a test tank of size, 1300 mm × 800 mm × 1100 mm. The experimental results indicate that the upward moments in batter anchor are more than the corresponding movements in vertical anchors. The ultimate uplift capacity of batter anchor is found to be less than the vertical anchor. This reduction in capacity is mainly due to the separation of the anchor from the soil at the bottom surface of the anchor which affects skin friction.
There are many coastal and offshore structures which are subjected to overturning moments due to wind and wave action and mooring and impact forces from ships. In several of these structures, batter piles are used along with vertical piles in groups. The behaviour of piles under either axial compression or uplift force has been well understood and various methods are available to predict the behaviour of vertical and batter piles subjected to pure axial loads. However, there are some field situations in which batter piles are subjected to vertical uplift forces and there are certain complications in assessing the behaviour of such types of piles. Meyerhof(1973) carried out an experimental study on model batter piles under axial pullout and concluded that the pullout resistance could be expressed in terms of uplift coefficients.
