根据Biot波动理论,采用复变函数与多级坐标法,求解了P波作用下饱和土体中地下输流管道的波动散射方程,分析了管道中流体介质性质、入射波角度及管道埋深等对地下输流管道周边动应力集中系数及孔压集中系数分布的影响。计算结果表明:在低频弹性波入射时,管道周边动应力集中系数及孔压集中系数分布相对均匀,而随入射频率的增加,其分布变得复杂化,但其峰值有所减小;中低频波入射作用下,管道内为水、石油介质时,动应力集中系数和孔压集中系数较空气介质时小,而在高频波作用时情况相反;对于管道内流体介质为水时,随着入射角度的变化,应力集中分布也沿一定角度的方向发生转动,入射波自管道下方垂直入射时,管道周边动应力集中系数峰值相对较大;随埋深的增加,动应力集中系数和孔压集中系数均呈震荡减小的趋势。
According to the Blot wave theory and the complex function combined with multi coordinate method, the wave scattering dynamical equation of liquid- filled pipe in saturated soil impacted by P waves is solved. The effects of fluid property in the pipe, incident wave angle and buried depth on the distributions of dynamic stress concentration coefficient and pore pressure concentration coefficient are analyzed. The results show that, in low frequency elastic wave incidence, dynamic stress concentration coefficient and pore pressures concentration coefficient are relatively uniform distributions around the periphery of the pipe; when the incident frequency increases, the distributions become complex, but the peak values decrease. In low or middle frequency elastic wave incidence, the dynamic stress concentration coefficient and pore pressure concentration coefficient of the pipeline filled with water or oil are relatively smaller than air medium. But in high frequency elastic wave incidence the opposite is the case. When the fluid medium in pipeline is water, the influences of the incident angle and depth of pipeline on the dynamic stress concentration coefficient and pore pressure concentration coefficient are analyzed. With the increasing of incident angle, the distribution also occurs at certain angle deflection. When the incident wave is perpendicular to the pipe, the peak value of pipe dynamic stress concentration coefficient around the periphery of the pipe is relatively large. With the increasing of depth, dynamic stress concentration coefficient and pore pressures concentration coefficient show shock decrease.