软硬混合地层盾构滚刀磨损规律研究——以北京市团城湖——第九水厂输水隧洞为例

Wear Law of Shield Disc Cutter of Shield Tunneling in Hard-Soft Mixed Strata of Water Conveyance Tunnel of Tuancheng Lake No.9 Water Plant in Beijing

为解决盾构滚刀在软硬混合地层掘进过程中磨损速度快、异常磨损严重等问题,基于北京市南水北调团城湖—第九水厂输水隧洞盾构施工刀具磨损现场监测数据,通过引入滚刀单位破岩体积磨损速率评价指标,对断层破碎带、全断面硬岩等软硬混合地层滚刀换刀数、异常磨损数进行回归分析;并结合滚刀异常磨损形式,对比分析不同地层滚刀磨损及失效规律。结果表明,滚刀磨损状态受平均磨损速率影响较大。滚刀在断层破碎带中异常磨损形式主要为偏磨、刀圈破坏,前者受平均磨损速率影响,后者主要是岩性不均使滚刀受异常冲击导致;滚刀在全断面硬岩中异常磨损形式主要为偏磨、镶齿脱落、刀圈破坏,镶齿脱落同样受平均磨损速率影响。最后,根据研究结果提出针对性的滚刀减磨措施。

The disc cutters wear rapidly and the abnormal wear is serious when shield tunneling in hard-soft mixed strata.Based on the on-site monitoring wear data of disc cutters of shield tunneling in the water conveyance tunnel of Tuancheng lake No.9 water plant of South-to-North Water Diversion Project in Beijing,the evaluation index of unit rock breaking volume wear rate is introduced to conduct regression analysis on the number of cutter change and abnormal wear in mixed strata such as fault fracture zone and full-section hard rock.Furthermore,the cutter wear and failure laws in different strata are compared and analyzed based on the abnormal wear modes.The results reveal that the cutter wear state is greatly affected by average wear rate.The main failure modes of disc cutter in fault fracture zone are eccentric wear and cutter ring failure.The eccentric wear is affected by average wear rate,while the cutter ring failure is mainly due to abnormal impact caused by uneven lithology.The main failure modes of disc cutter in full-section hard rock are eccentric wear,cutter ring failure,and insert loss.The insert loss is also affected by average wear rate.Additionally,corresponding cutter wear reduction measures are proposed according to the research results.