中文摘要：

基于盾构隧道典型4孔同步注浆的特点,建立盾构-浆液-土体相似系统和模型试验平台,开展不同注浆方式下的室内相似模型试验,研究盾尾空隙内浆液压力的分布规律及消散过程、浆液的流动路径及扩散方式。结果表明：注浆方式对浆液压力的有效影响范围主要集中在盾尾后方2倍隧道直径范围内;利用上部注浆孔或下部注浆孔单独注浆都是不科学的;上部或下部浆液流量大于等于60%时,其流量变化对浆液压力初值的分布具有决定性作用;上部浆液流量在60%~80%之间才能确保浆液压力初值较好地适应地层应力;盾尾空隙最佳充填模式为,单孔注浆时应采用上部注浆孔,双孔同步注浆时应采用上下双孔注浆且上部浆液流量约占总流量的80%,4孔同步注浆时上部浆液流量应占总流量的60%~80%;刚注入的浆液主要分布在注浆孔附近区域,单位时间内新形成的盾尾空隙主要由原来盾尾处呈流塑状的浆液进行充填;建议在拱顶附近预留专用注浆孔进行二次补注浆。

英文摘要：

Based on the typical four-hole simultaneous backfill grouting adopted during shield tunneling, the shield-grout-soil similar system and test platform were correspondingly set up and the indoor similar model tests were carried out under different grouting modes. The grout pressure distribution in the void of shield tail, dissipation process flow path and diffusion pattern were studied. The results show that the effective influence range of grouting mode on grout pressure is mainly confined in two times as tunnel diameter away from shield tail. Using one grouting hole only is unscientific, no matter for the lower part or the upper part. The change of grout flow plays a decisive role on initial grout pressure when the grout flow of the lower part or the upper part is greater than or equal to 60%. In order to realize the ideal adap- tion of initial grout pressure and formation stress, the grout flow at the upper part should be between 60% and 80 ~. The optimal backfill grouting mode for the void of shield tail is put forward. Namely, the upper grouting hole should be adopted for single hole grouting mode; both the upper and lower grouting holes should be adopted for two-hole simultaneous grouting mode and the upper grout flow should be about 80% of the total; the upper grout flow should be between 60%~80% for four-hole grouting mode. The grout being just injected into tail void will be mainly distributed around the grouting hole, and the newly formed tail void per unit time will be mainly filled by the previous flow-plastic grout nearby. As for the secondary filling grouting, the reserved specific grouting hole near the vault should be arranged.