Abstract The studied area is a part of the New Istanbul Airport Metro construction project, which is on the Northwest of the city center towards the Black Sea Coast on the European Side of Istanbul. For this project ten EPB-TBMs were used. Two of them jammed/blocked consecutively within complex weakness zones as loose and open crushed zones. These zones have a complex geometry and structure filling with materials having very low strength characteristics. Squeezing occurred in both tubes of the first line. EPB-TBMs jammed three times in the first tube and once in the second tube. Apart from waiting time and using of lubricating agents, the effect of EPB pressure on reducing TBM jamming/blocking risk is explained. Mean EPB pressure applied in the second tube within studied chainages was 1.65 bar which was almost twice than the one used in the first tube (0.83 bar) making an increase in mean thrust force of 20% and increase in the mean torque values of 10% compared to ones obtained in the first tube. However, it is observed that higher EPB pressures helped stopping the collapses of loose materials within complex weakness zones. The methodology of salvation operations, mitigations measures as injecting bentonite, polymers and using additional cylinders are discussed within the paper and it is believed that the results will serve as basis to understand better the squeezing mechanism of such complex structures and to help to take correct mitigation measures in future EPB-TBM drives. In complex geologies in similar weakness zones it is proved that foam lubricants are not best choices and additional thrust cylinders are a necessity.

中文翻译：

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对理解复杂地质构造中的 EPB-TBM 驱动的贡献

摘要 研究区是伊斯坦布尔新机场地铁建设项目的一部分，位于市中心西北部，靠近伊斯坦布尔欧洲一侧的黑海海岸。该项目使用了 10 台 EPB-TBM。其中两个在复杂的薄弱区域内连续卡住/阻塞，作为松散和开放的压碎区域。这些区域具有复杂的几何形状和结构，填充有强度非常低的材料。第一行的两个管子都发生挤压。EPB-TBM 在第一个管中堵塞了 3 次，在第二个管中堵塞了一次。除了等待时间和润滑剂的使用外，还解释了 EPB 压力对降低 TBM 堵塞/阻塞风险的影响。在研究的里程数内，施加在第二个管中的平均 EPB 压力为 1。65 巴几乎是第一管中使用的压力 (0.83 巴) 的两倍，与第一管中获得的相比，平均推力增加了 20%，平均扭矩值增加了 10%。然而，据观察，较高的 EPB 压力有助于阻止复杂薄弱区域内松散材料的坍塌。论文中讨论了拯救操作的方法、注入膨润土、聚合物和使用额外圆柱体的缓解措施，相信结果将作为更好地理解这种复杂结构的挤压机制并有助于采取正确缓解措施的基础。未来 EPB-TBM 驱动器的措施。在类似薄弱区域的复杂地质中，事实证明泡沫润滑剂不是最佳选择，需要额外的推力油缸。