针对砂卵石地层盾构长距离掘进工程特点，提出先行刀多维度梯次布置的设计理念，“多维度”保证了长距离掘进中刀盘受力稳定，不同刀高的先行刀梯次布置使其合金块之间搭接形成合金块磨损接力。同时优化先行刀合金块的耐磨及耐撞击性能，避免在长距离掘进中存在的刀具冲击疲劳失效。依托北京新机场线“磁1”区间盾构工程，通过方案比选得到最终刀盘设计方案，并对掘进过程中掘进刀具磨损数据与掘进参数进行深入分析。数据分析结果表明：多层先行刀布置的盾构砂卵石地层长距离掘进可分为高刀犁松和高低刀共同犁松两个阶段，高刀犁松阶段“梯次化”布置的高刀降低了低刀的磨损系数，高低刀共同犁松阶段在一定距离内继续维持掘进效率，有效延长掘进距离。

To optimize long-distance shield tunneling in gravel stratum, the concept of a multi-dimensional gradient layout of advanced cutters is proposed. The multi-dimensional layout ensures the stability of the cutter head during long-distance excavation, and the gradient layout allows alloy blocks of advanced cutters with different heights to overlap in order to realize wear “relay.” In this study, we selected the most suitable design for the project after comparing several cutter heads and cutter layouts. Meanwhile, the wear resistance and impact resistance of the alloy blocks were optimized to avoid impact fatigue failure during long-distance excavation. Based on the engineering of the section from Cigezhuang Station to No. 1 Air Shaft in the Beijing New Airport Metro line, the final cutter head design scheme was obtained through scheme comparison and selection. Furthermore, the cutting tool wear results and tunneling parameters in the tunneling process were analyzed. The data show that long-distance tunneling in a gravel stratum with multi-layer advanced cutters can be divided into two stages: plowing primarily with a high cutter and plowing with both high and low cutters. In the first stage, the wear coefficient of the 155 mm advanced cutters is reduced because of the cutters with a height of 190 mm. In the second stage, normal tunneling can be maintained within a certain distance, which means that the tunneling distance can be extended. Therefore, this can provide a reference for similar engineering constructions in the future.

U45

国家自然科学青年科学基金项目(51608521)；北京市教委成果转化与产业化项目(ZDZH20141141301)