An indirect boundary integration equation method (IBIEM) of high precision is used to analyze the vibration isolation effect of the two-dimensional discontinuous pile-group barriers on plane P and SV waves within a broad band of frequency. This method is based on the single layer potential theory

and the scattered field in vivo and vitro of the scatterer is constructed using the fictitious wave sources close to the surfaces of discontinuous barriers. The magnitude of the fictitious wave sources are determined by boundary conditions

while the total response can be obtained by the superposition of free field and scattered field. It is shown that the proposed method has excellent numerical accuracy in solving broadband isolation vibration problems related to arbitrary arranged piles. For the elastic cylindrical solid pile

the frequency spectrum is quantitatively analyzed

showing that different vibration isolation effects of elastic rowed piles are associated with different ranges of frequency with the incidence of P and SV waves. The vibration isolation effect for different wave velocity ratios

different distances of piles and different rows of piles are discussed

and it is shown that: 1) there exist optimal dimensionless frequencies for prominent vibration isolation effect; and thus it is necessary to carry out optimization design of pile diameter and pile spacing; 2) for softer soil

the isolation effect becomes better

and compared to P wave

SV waves is more sensitive to the pile spacing; 3) Multiple rows of piles should be adopted for low frequency waves

but for the high frequency wave

more than three rows of piles will not lead to significant improvement on the vibration isolation effect.