不同脱困方式爆破下复合支护结构动态响应

Dynamic Response of Composite Support Structures Under Different Blasting Methods for TBM Breakout

  • 摘要: 为系统定量分析双护盾TBM(盾体)在高地应力硬岩卡机后不同脱困爆破方式下支护结构的动态响应特征和安全范围,以多雄拉公路隧道卡机段为例,采用SoildWorks和Hypermesh建立数值模型,运用LS-DYNA计算分析高地应力下微差爆破对支护结构的动态影响,在此基础上以峰值振速为关键指标,探究微差爆破相较于同步爆破的优势,并划定不同爆破荷载影响下支护结构的安全范围。研究结果表明:支护结构最大峰值振速位于近爆破区间中心位置,并随爆破进尺深度的增加而逐渐增大,出现时间相应提前,尤其是第5和第6爆破进尺显著高于其他进尺。相较于同步爆破,微差爆破能有效降低爆破荷载对复合支护结构的动态影响,对于第5和第6爆破进尺,微差爆破下峰值振速降幅可达42.3%,显著减小支护结构不安全范围。

     

    Abstract: To systematically and quantitatively analyze the dynamic response characteristics and safety ranges of support structures under different blasting methods for releasing a double-shield TBM (shield body) jammed in high-stress hard rock, this study takes the TBM jamming section in the Duoxiongla Highway Tunnel as an example.Numerical models were established using SolidWorks and Hypermesh, and LS-DYNA was employed to calculate and analyze the dynamic effects of millisecond-delay blasting on support structures under high geostress. Based on this, with peak particle velocity (PPV) as the key indicator, the advantages of millisecond-delay blasting over simultaneous blasting were investigated, and the safety ranges of support structures under different blasting loads were delineated. The results show that the maximum PPV of the support structure occurs near the center of the blasting zone and gradually increases with the advance depth of blasting, with the occurrence time advancing correspondingly. Notably, the 5th and 6th blasting advance rounds exhibit significantly higher PPVs than other advance rounds. Compared to simultaneous blasting, millisecond-delay blasting effectively reduces the dynamic impact of blasting loads on composite support structures. For the 5th and 6th blasting advance rounds, millisecond-delay blasting reduces PPV by up to 42.3%, significantly shrinking the unsafe range of the support structure.

     

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