盾构刀盘复合地层下冲击载荷分析

Analysis of impact load under the compound stratum of shield cutter head

提出一种复合地层中刀盘极限冲击载荷计算新方法,对此类不良地质中刀盘的安全设计进行分析并提出改进思路。由于盘形滚刀和切刀在上软下硬地层中受周期性冲击载荷作用,通过对刀具进行受力分析并建立力学模型,得到刀具沿隧道轴线方向受到的交变载荷最大值与刀具贯入度以及硬岩高度的关系。刀具受到的最大载荷传递到刀盘上,通过计算刀盘所受载荷,对比软硬不同地层中刀盘上部和下部载荷的差值,计算并分析刀盘所受沿隧道轴线方向的力和倾覆力矩。计算结果表明,该方法对上软下硬复合地层中刀盘的极限载荷计算和安全分析有较好的效果。

A new method for calculating the ultimate loads of the cutter head for composite formations was proposed.The safety design of the cutter head in the unfavorable geology was analyzed and improvements were put forward.Since the disc hob and cutter tools are subject to periodic impact loads in the upper-soft and lower-hard strata,the relationship among the maximum alternating load on cutters along the tunnel axis,the penetration of cutters and the height of the hard rock was obtained by analyzing the force on cutters and establishing a mechanical model.The maximum load on the cutter head was transferred to the cutting tool.By calculating the loads on the cutter head,and comparing the difference between the minimum and maximum loads on the cutter head for different strata,the force and overturning moment on the cutter head along the tunnel axis direction were calculated and analyzed.The calculation results show that the method has a good effect on the ultimate loads calculation and safety analysis of the cutter head in the upper-soft and lower-hard strata.