隧道掘进机滚刀破岩动态荷载理论模型及试验研究

Theoretical and experimental study of tunnel boring machine dynamic cutting force

滚刀荷载的动态信息(如峰值荷载、增长速度以及频率等)对保持全断面隧道掘进机系统稳定、控制刀盘振动等至关重要。目前的破岩力预测公式不足以满足刀盘受力及振动的求解需要。因此,基于离散化建模思路,将传统空腔膨胀理论的一维贯入运动扩展至高维度的回转破岩中,对岩体参数及操作参数对荷载特性的影响进行了研究。并通过多组全尺寸回转破岩试验进行验证。结果表明:安装半径、转速以及贯入度的增大使单位时间内滚刀挤压的岩体体积增多、密实核边界速度升高,导致侵岩荷载的增长速度及频率均升高,荷载变化及刀盘振动更加剧烈。岩体强度的增大会导致荷载峰值及增长速度升高、频率降低。所建立的回转破岩动态荷载理论模型与试验结果相差5%以内,验证了该模型的准确性。

Dynamic information about the cutter force,such as peak load,growth rate and frequency,is critical to maintaining the stability of the tunnel boring machine system and controlling cutterhead vibration.The current cutting force prediction formula cannot meet the solutions of the thrust and vibration of the cutterhead.Based on the idea of discrete modeling,the one-dimensional penetration of the traditional cavity expansion theory is extended to high-dimensional rotary rock test.The influence of rock mass parameters and operating parameters on the force is studied.And the full-scale rotary cutting test is used to verify the theory.The results show that the increases in installation radius,speed and penetration cause an increase in the volume of rock mass extruded by the cutter,and an acceleration in the boundary velocity of the core.It contributes to increase in the growth rate of cutter force and frequency of the cutterhead vibration.The higher strength of the rock mass leads to higher force peak value,growth rates and lower frequencies.The dynamic cutting force model differs from the test results within 5%,indicating the accuracy of the model.