EFFECT OF SEDIMENT MODEL ON DYNAMIC PRESSURES OF SUBMERGED FLOATING TUNNEL DUE TO SV WAVE INCIDENCE
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摘要: 为研究地震SV波对复杂海水环境中悬浮隧道管体动力水荷载的影响,考虑海洋沉积淤砂层的作用构建理论分析模型。根据不同介质材料的波动方程和位移势函数,结合地震SV波传播过程中的边界条件,基于MATLAB推导并求解了不同交界面处地震SV波的透射和反射系数理论方程。通过数值算例,分析了淤砂层饱和程度、入射波角度和锚索布置形式等参数对悬浮隧道管体动力水荷载的影响。计算结果表明:悬浮隧道结构在非饱和淤砂层体系中,相比在饱和淤砂层体系中承受更大动力水荷载的影响;较厚淤砂层对悬浮隧道在地震SV波作用下更为有利;增加锚索支撑刚度和减小锚索布置间距,能够降低地震SV波对悬浮隧道动力水荷载的影响。Abstract: To study the dynamic pressure acting on the submerged floating tunnel (SFT) under the seismic SV wave in complex seawater environment, a theoretical analysis model is proposed considering the marine sediment effect. Based on the wave equations and displacement potential functions of different media materials, the theoretical equations of wave transmission and reflection coefficients at different interfaces are deduced and solved on MATLAB through the seismic SV wave propagation boundary. Numerical examples are employed to illustrate the effects of the saturation of the sediment, the incident SV-wave angle and the layout of tether on the dynamic pressure on the SFT. The results show that the unsaturated sediment has greater effect on the dynamic pressure on the SFT than that of the saturated sediment. Thicker sediment is more benefit to the SFT under the action of seismic SV wave. And increasing the tether stiffness or decreasing the tether spacing can reduce the dynamic pressure on the SFT.
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Key words:
- submerged floating tunnel /
- wave equation /
- two-phase porous medium /
- seismic SV wave /
- dynamic pressure
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表 1 不同介质层交界面处的水动力荷载
Table 1. Dynamic pressure results at the interface of the system
入射角θ=25° 水深 $h_1^ - $ $h_1^ + $ dev $h_3^ - $ $h_3^ + $ dev 无淤砂层 3.05 3.05 0.00 1.64 1.21 −0.43 饱和淤砂层 2.86 2.87 0.01 1.55 1.21 −0.34 非饱和淤砂层(99.5%) 3.70 4.02 0.32 1.83 1.39 −0.44 入射角θ=45° 水深 $h_1^ - $ $h_1^ + $ dev $h_3^ - $ $h_3^ + $ dev 无淤砂层 3.46 3.46 0.00 1.79 1.43 −0.36 饱和淤砂层 3.29 3.30 0.01 1.71 1.42 −0.29 非饱和淤砂层(99.5%) 4.53 4.90 0.37 2.11 1.72 −0.39 注:dev表示h+与h−交界面处的动水压力差值。 -
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