铁道标准设计2025，Vol.69Issue(6)：143-150,157,9.DOI:10.13238/j.issn.1004-2954.202307120006
弧形撕裂刀切削钢筋混凝土桩基仿真与实践
Simulation and Practice of Cutting Reinforced Concrete Pile Foundations with Curved Tearing Cutters
摘要
Abstract
To investigate the interaction mechanism between the cutter and pile foundation during shield machine pile-cutting operations and to prevent cutter damage,a study was conducted using the shield tunneling project involving group piles on Nanjing Metro Line 10 as the background.Based on the RHT and Johnson-Cook(J-C)constitutive models,a numerical model of a curved tearing cutter cutting through reinforced concrete composite was established.The failure mechanism of reinforced concrete was clarified,and the influence of cutting parameters on cutting forces was analyzed.Finally,the cutting performance was evaluated through comparison with actual engineering data.The main conclusions were as follows:(1)under repeated cutting by the cutter,concrete underwent extensive damage,the bond and contact between rebar and concrete fail,the confinement effect of concrete on rebar was reduced,significant bending deformation of the rebar occurred,and the cut surface exhibited a compression-tension fracture pattern.(2)When the curved cutter operated at a cutting speed of 0.3 m/s and penetration depth of 3 mm,the cutter edge stress reached a maximum of 2.6 GPa upon penetrating 6 mm into the rebar,which was below the allowable stress limit of 2.8 GPa for alloy materials,indicating no risk of cutter edge fracture.(3)Within a cutting speed of 0.2～0.5 m/s and penetration depth of 1.5～7.5 mm,the cutting force was weakly affected by speed but increased significantly with deeper penetration.In practical engineering,a pile-grinding mode using high rotational speed and low penetration depth was recommended to avoid cutter failure.(4)During pile cutting,increases in thrust and torque were limited.Rebar cutting patterns were classified as extrusion scratches,extrusion-tension fractures,and full tensile fractures.No cutter edge fractures were observed.However,the welding strength between the alloy cutter edge and the body of the tearing cutter was a critical aspect that would require attention in similar projects.关键词
盾构切桩/弧形撕裂刀/钢筋混凝土耦合体/切削参数/数值仿真/工程实践Key words
shield pile cutting/curved tearing cutter/reinforced concrete composite/cutting parameters/numerical simulation/engineering practice分类
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梅君,崔伦萌,陈裕康,李兴高,闵凡路,方应冉..弧形撕裂刀切削钢筋混凝土桩基仿真与实践[J].铁道标准设计,2025,69(6):143-150,157,9.基金项目
国家重点基础研究发展计划(973计划)项目(2015CB057802) （973计划）
