Effect of pile installation method to load carrying capacity of piles

The construction of piles by driving method causes an increase in density of surrounding soils. Therefore for loose soils this leads to improved compaction of soils between the piles. Sum of the capacities of all piles as a whole is normally greater than the sum of individual pile capacities provided that effect of pile spacing isn't taken into account. Though for bored piles the boring operation persuades considerable stress relief and this causes a substantialreduction in shear strength of soils.