中文摘要：

土压平衡盾构在无水砂卵石地层掘进过程中,刀具磨损严重,需频繁更换刀具,影响工程进度。文章在分析主动换刀方式和被动换刀方式优缺点的基础上,结合北京地铁9号线03标工程实例,分析了两种换刀方式对工程进度的影响,并就无水砂卵石地层合理换刀距离和刀具磨损规律进行了研究。结果表明：主动换刀方式具有换刀时间短、对工期影响小等优点,适用于无水砂卵石地层;在北京地区西南部大粒径砂卵石地层中,辐条式盾构的合理换刀距离在300 m;土压平衡盾构在无水砂卵石地层掘进过程中,刀盘扭矩和推力并不是随着刀具的磨损而逐渐增大,而是在刀具磨损非常严重时突然增大,且在9.6 m的短距离内达到极限磨损状态,因此无法通过刀盘扭矩和推力的变化情况来提前规划换刀距离和位置。

英文摘要：

Considering that serious wear and frequent replacement of the cutter may affect the construction prog- ress of an EPB shield while tunnelling in a waterless sandy cobble stratum, and using the construction of Lot 3 of Beijing Metro line 9 as an example, this paper analyzes the influences of active and passive cutter replacement tech- niques on construction progress based on their merits and demerits and establishes the reasonable distance for cut- ter replacement and the cutter-wear rule for this type of stratum. The results show that the active cutter replacement technique has the advantages of quick cutter replacement and little influence on the construction schedule, which is appropriate for this stratum; the reasonable distance for cutter replacement is 300 m for a shield with a spoke-type cutterhead during driving in a waterless stratum with large-particle cobbles in southwest Beijing; the distance and location for cutter replacement cannot be planned ahead based on the variation of the cutter torque and shield thrust because the cutter torque and shield thrust could increase suddenly in the case of serious cutter wear, and the limit wear state would be reached even in the short excavation distance of 9.6 m.