Soil Dynamics and Earthquake Engineering ( IF 4 ) Pub Date : 2021-02-20 , DOI: 10.1016/j.soildyn.2021.106655 Bei Zhang , Yu Huang
Barrier design considering the coupling effect of flow impact and seismic shaking is challenged and has not been covered in previous researches, thus we performed numerical simulations to obtain fundamental insights on this matter. The influence and mechanism of the effects of shaking direction and magnitude on the impact processes of dry granular flow are investigated using a range of slope angles. Slope-normal shaking exhibits the most significant influence on flow mobility. Under 0.99 g, the maximum velocity is enhanced by 10.23% and the accumulative kinetic energy increases by 8.12%, which is caused by the coupled effect of reduced frictional resistance and energy supplement, where the latter dominates. Slope-longitudinal shaking exerts a more significant effect on the impact force, showing that the overall peak force increases by 42.14% under 0.99 g shaking, which implies that the enhanced mobility is not the main cause of enhanced impact effect but the evolution of dead zone, whose stability is altered by seismic shaking bringing and leads the barrier design load to largely exceed the value required by traditional design strategies. The influence of shaking on granular flow impact dynamics is substantially more significant when the flow conditions are gentle: the normalized force discrepancy is reduced from 77.05% to 41.36% when the slope angle is increased from 25° to 40° under 0.99 g slope-longitudinal shaking. In addition, the limitations of current models and direction for future work are discussed, including the effect of the fluid phase in debris flow, real seismic ground motion, and barrier types.
中文翻译:
颗粒流的地震震动增强冲击效应挑战了屏障设计策略
考虑流动冲击和地震振动耦合效应的障碍设计面临挑战,并且在先前的研究中并未涉及,因此我们进行了数值模拟以获得对该问题的基本见解。利用一定的倾斜角度,研究了振动方向和幅度对干颗粒流冲击过程的影响及其机理。正常坡度摇动对流动性影响最大。在0.99 g以下时,最大速度增加了10.23%,累积动能增加了8.12%,这是由于减小的摩擦阻力和能量补充(主要是后者)的耦合作用引起的。纵向倾斜振动对冲击力产生更大的影响,表明总峰值力增加了42。在0.99 g震动下为14%,这表明增强的活动性不是增强撞击效果的主要原因,而是死区的演变,死区的稳定性会因地震震动而改变,从而导致屏障设计载荷大大超过了设计要求。传统设计策略。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾角从25°增大到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。这意味着增强的流动性不是增强碰撞效果的主要原因,而是死区的演变,死区的稳定性会因地震震动而改变,从而导致屏障设计载荷大大超过传统设计策略所需的值。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾角从25°增大到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。这意味着增加的流动性不是增加碰撞效果的主要原因,而是死区的演变,死区的稳定性会因地震的震动而改变,从而导致障碍设计负荷大大超过传统设计策略所需的值。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾斜角从25°增加到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。其稳定性会因地震震动而改变,并导致屏障的设计载荷大大超过传统设计策略所需的值。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾角从25°增大到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。其稳定性会因地震震动而改变,并导致屏障的设计载荷大大超过传统设计策略所需的值。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾角从25°增大到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾角从25°增大到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。当流动条件温和时,摇动对颗粒流动冲击动力学的影响显着更大:当在0.99 g坡度纵向上将倾斜角从25°增加到40°时,归一化力差异从77.05%减小到41.36%。颤抖。此外,还讨论了当前模型的局限性和未来工作的方向,包括流体相对泥石流的影响,实际地震运动和障碍类型。