| 摘要(英) |
The paper is to
investigate the screening effectiveness of strip foundation subjected to
vertical harmonic vibration using in-filled trenches and sheetpiling
trenches. Two-dimensional boundary element method in frequency domain is
used in this study. The main parameters are considered in this study,
including dimensions of in-filled trenches and sheetpiling trenches,
such as width, depth, cross-sectional area, and position of trench,
impedance ratio, density ratio, and velocity ratio of in-filled
material, and the material properties of sheetpiling. To study the
efficiency of wave isolation, vertical average amplitude reduction ratio
behind trench was analyzed. For vertical vibration analysis, the
optimized depth and width of in-filled trench is suggested to be 1.0 Lr
and 0.8 Lr respectively, in which Lr is defined to be the Rayleigh
wavelength. The optimized distance between the in-filled trench and
foundation is about 4 Lr. The more difference of the impedance ratio or
velocity ratio, the better wave isolation is. For vertical vibration
analysis, using of sheetpiling trench as barrier, the position of
sheetpiling trench is insignificant on the screening effectiveness. The
Screening effectiveness of the sheetpiling trench dimension is different
because of the material of sheetpiling. |
