ANALYTICAL STUDY OF MULTIPLE UNDER REAMED PILE BY GEOMETRICAL VARIATIONS AND LOADING CONSIDERATIONS

Abstract

When the water table is high, good foundation is not available at an adequate depth, under such circumstances casting of simple pile is most uneconomical. To overcome these conditions, under reamed pile is the best option. The under-reamed pile are casted in an expansive soil. The piles are constructed to transfer the load of heavy structures as high rise structures, industrial structures transmission towers. The bulbs are provided at an adequate depth to normal pile shaft and this pile is known as under-reamed pile. As per the requirement of loads, number of bulbs are provided to pile shaft. As the number of increases, load bearing capacity of pile also increases. Paper deals with analysis of one, two and three bulbs of under-reamed R C C circular piles. All three types of piles were analyzed for number of loading conditions and variable geometrical condition was considered. In case I single bulb under reamed circular R C C pile was taken into account. (1) Different parameters for Stem diameter (D) and length (L) of pile were considered Thus ultimate bearing capacity (Qu) of pile was obtained. In case II for single bulb pile (2) Substituting various dimensions were considered for ultimate bearing capacity (Q u) and different parameters were provided to diameter to stem (D). With the help of these two variables, required length of pile (L) were obtained. In case III for same pile (3) Different magnitude of ultimate bearing capacity (Qu) and for different length of pile (L) , the required diameter of stem (D) was obtained. All the above mentioned three cases were applied for two bulb and three bulb piles. All the results thus obtained were shown in tabular form. The results obtained will provide adequate guidelines to civil engineers and contractors.