砂卵石地层盾构刀具磨损预测模型及刀具参数敏感性分析

Prediction Model for Gravel Stratum Shield Cutter Wear and Parameter Sensitivity Analysis of Cutter Parameters

[目的]砂卵石地层中的石英颗粒体积分数较高,会导致盾构刀具磨损严重,影响施工进度及工期。建立盾构刀具磨损预测模型来预测盾构刀具的磨损量,是确保盾构法施工高效安全进行的重要环节。因此,有必要研究刀具磨损预测模型,并进行刀具参数敏感性分析。[方法]分析了砂卵石地层对盾构刀具的研磨性;介绍了砂卵石地层盾构刀具的切削机理;建立了考虑微观磨损特征的盾构刀具磨损预测模型,并对刀具参数进行敏感性分析。[结果及结论]不均匀系数、特征粒径与材料的磨损量正相关;塑性去除磨损、脆性去除磨损和黏着磨损的体积分数分别为61.4%、30.8%、7.8%,塑性去除磨损和脆性去除磨损占比较大;磨损系数随着不均匀系数和特征粒径的增大而增大,盾构刀具的磨损量整体随着刀具刃角的减小而减小。盾构刀具的磨损主要由磨粒磨损和黏着磨损造成。

[Objective]The high volume fraction of quartz particles in gravel stratum can lead to significant wear of shield cutters,impacting construction progress and timelines.Establishing a prediction model for shield cutter wear to forecast the extent of cutter wear is a crucial procedure to ensure efficient and safe shield tunnel construction.Therefore,it is necessary to study the cutter wear prediction model and conduct sensitivity analysis of cutter parameters.[Method]The abrasive nature of gravel stratum on shield cutters is analyzed,and the cutting mechanism of shield cutters in gravel stratum is introduced.A shield cutter wear prediction model that considers micro-level wear characteristics is established,and a sensitivity analysis of cutter parameters is conducted.[Result&Conclusion]The non-uniformity coefficient,characteristic particle size,and material wear are positively correlated.The volume fractions of plastic removal wear,brittle removal wear,and adhesive wear are 61.4%,30.8%,and 7.8%,respectively,with plastic removal and brittle removal wear accounting for a significant proportion.The wear coefficient increases with increasing non-uniformity coefficient and characteristic particle size,while the overall wear of shield cutters decreases with the decreasing cutter edge angle.The wear of shield cutters is mainly caused by abrasive wear and adhesive wear.