基于岩渣粒径分布规律的TBM 刀具消耗分析

Analysis on TBM cutter consumption based on the particle size distribution of rock debris

  • 摘要: 岩渣是TBM掘进过程中岩机作用的直接产物,其粒径分布规律是进行TBM地质适应性、掘进效率和刀具消耗评价的重要指标。针对刀具消耗评价问题,结合兰州水源地建设工程输水隧洞双护盾TBM施工,对TBM在不同岩体条件中掘进时产生的岩渣进行了现场量测与筛分试验,并对实测岩渣粒径分布数据进行了统计分析和理论分布函数拟合。对TBM掘进过程中刀具消耗规律进行了分析总结,探讨了不同岩体条件下TBM刀具消耗规律与岩渣粗糙度指数、岩渣颗粒级配系数以及岩渣粒径分组比例等参数之间的相关关系。研究结果表明:① 刀具消耗与岩体地质条件密切相关,岩石强度越高,耐磨性越强,刀具消耗越大,Ⅱ类和Ⅳ类围岩中TBM刀具消耗明显高于Ⅲ类围岩;滚刀直径对刀具消耗有一定影响,采用大直径滚刀可降低同等围岩条件下的刀具消耗;② 不同岩性条件下岩渣粒径分布不均匀,总体上属于级配良好,符合Rosin-Rammler函数,可采用Rosin-Rammler函数进行岩渣粒径分布参数计算;③ 刀具消耗与岩渣曲率系数的相关性不明显,与不均匀系数存在较好的二次函数关系,相关系数为0.875;④ 刀具消耗与岩渣粗糙度指数存在较显著的二次函数关系,相关系数为0.87,当岩渣粗糙度指数大于430时,岩渣粗糙度指数越高,TBM掘进效率越高,刀具消耗越小;⑤ 刀具消耗与岩渣几何平均粒径、R-R函数平均粒径呈正相关性,相关系数为0.84;⑥ 刀具消耗与岩渣形状含量比例之间密切相关。硬岩片状岩渣含量多时,刀具消耗较小,当片状岩渣含量大于40%时,刀具消耗降低速率加快;而块状与粉状岩渣多时,刀具消耗较大,当块状岩渣含量大于40%时,刀具消耗增加速率增高。研究成果建立了TBM刀具消耗与岩渣粒径分布规律之间的有效联系。

     

    Abstract: The rock debris is produced by rock-machine interaction during TBM excavation.The rock debris and its particle size distribution are crucial and effective indexes to evaluate TBM geological adaptability,tunneling efficiency and cutter consumption.In terms of the problem of cutter consumption evaluation of double shield TBM in water conveyance tunnel of Lanzhou water source construction project,the in-situ measurement and screening tests of TBM rock debris for different rock mass conditions were carried out.The measured data of rock debris particle size distribution were statistically analyzed and fitted with the theoretical distribution function.The characteristics of TBM cutter consumption was summarized.On above basis,the relationships between TBM cutter consumption under different rock mass conditions and some particle size distribution parameters of rock debris,i.e.coarse index (CI),particle gradation coefficient and category ratio were discussed.The results show that the cutter consumption is closely related to rock mass and geological conditions.The higher the rock strength and abrasiveness,the more the cutter consumption.TBM cutter consumption in the surrounding rocks of class II and IV is significantly higher than that in the surrounding rocks of class III.The cutter diameter has a certain influence on the cutter consumption,large diameter cutters can reduce the consumption under the same surrounding rock conditions.For different lithology conditions,the particle size distribution of rock debris is uneven,which is generally well graded.The particle size distribution of rock debris conforms to the Rosin-Rammler function,and the Rosin-Rammler function can be used to calculate the particle size distribution parameters of rock debris.The correlation between cutter consumption and rock debris curvature coefficient is not obvious,while there is a good quadratic function relationship between cutter consumption and rock debris inhomogeneity coefficient,and the correlation coefficient is 0.875.Meanwhile,there is a significant quadratic function relationship between cutter consumption and the coarse index of rock debris,and the correlation coefficient is 0.87.When the coarse index is higher than 430,the higher the coarse index of rock debris is,the higher the TBM tunneling efficiency is,and the smaller the cutter consumption is.The cutter consumption is positively proportional to the average particle size of rock debris including geometric average particle size and R-R function average particle size,and the correlation coefficients are 0.84.The cutter consumption is closely related to the proportion of debris shape and its content.The higher the rock chip content is,the smaller the cutter consumption is.When the content of flaky debris is more than 40%,the decrease rate of cutter consumption decreases faster.When the content of rock blocks and powder increase,the cutter consumption also increase.When the content of block debris is more than 40%,the increase rate of cutter consumption is faster.The research results establish an effective relationship between TBM tool consumption and rock slag particle size distribution.

     

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