Theoretical analysis of a row of piles as passive barriers and an equivalent in-filled trench model

GAO Guang-yun(高广运)^{1, 2}, SONG Jian(宋健)^{1, 2}, YANG Jun(杨峻)³

(1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China;
2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education
(Tongji University), Shanghai 200092, China;
3. Department of Civil Engineering, The University of Hong Kong, Hong Kong, China)

Abstract:A theoretical study on the ground vibration isolation efficiency by a row of piles as passive barrier in a three-dimensional context was presented. The analysis was accomplished with the aid of integral equations governing Rayleigh wave scattering, used to predict the complicated Rayleigh wave field generated by a number of irregular scatters embedded in an elastic half-space. Then, the passive isolation effectiveness of a row of piles for screening Rayleigh wave was studied in detail. The effects of relevant parameters on the screening effectiveness were investigated and analyzed from the perspective of equivalence with in-filled trench. The results show that using a row of rigid piles as wave barrier is more effective than that of flexible ones, and an optimum reduction of vibration can be achieved either by increasing the size of piles or by decreasing the net spacing between the piles. Finally, based on the derived integral equation for Rayleigh wave scattering, the principle of equivalent modeling of the barrier of piles by an in-filled trench is put forward, which simplifies the analysis of vibration isolation by a row of piles.

Key words:Rayleigh wave scattering; integral equation; piles; in-filled trench; ground vibration; passive isolation; equivalence principle