Semi-analytical BEM-FEM analysis of vibration isolation of a row of SDMC pile in saturated soil

Ground-borne vibrations are generated by traffic and machinery operations, which may then be transmitted to adjacent structures, causing them to be distressed and the operation of precision instruments to be disturbed. A new kind of environmental-friendly pile, called stiffened deep cement mixing (SDCM), is introduced to construct wave barriers in the city. A three-dimensional semi-analytical framework that couples boundary and finite elements is developed; within it, the influence of each model parameter on vibration-isolation performance is systematically examined. Simulations demonstrate that a single line of SDCM piles effectively mitigates ground-borne vibrations. Better vibration isolation is achieved when the number of SDCM pile rows with equally spaced core piles is increased, compared with when short core piles are used. Additionally, the screening efficiency is only marginally influenced by the clear spacing between adjacent piles. According to the results, the hole radius should be 2∼3 λ R ( λ R is the Rayleigh wave length) in the design. Furthermore, the SDCM pile wave barriers, which are made up of different precast core piles with the same overall dimension, can result in approximately equivalent screening efficiency.