盾构切刀切削混凝土过程中的动态响应试验

为探究盾构切刀与混凝土的相互作用规律,开展室内切削试验,验证切削的实质是刀具与试件反复碰撞、挤压、切削和剥落的循环过程.通过切削力测试系统得到刀具前后角、刀具形状、切削深度和试件强度等因素对刀具法向切削力Fn与切向切削力Ft的影响规律,并分析得到各影响因素作用下Fn、Ft及切削合力Fc的波动范围.结果表明:刀具切削混凝...

Dynamic response mechanism of shield cutter in concrete cutting

To investigate the interaction between shield cutter and concrete, laboratory cutting experiments were carried out, which verified that the essence of cutting is the cyclic process of collision, extrusion, cutting, and peeling between cutter and specimen. The influence of tool rake and clearance angles, tool shape, cutting depth, and specimen strength on the normal cutting force F_n and tangential cutting force F_t of the tool was obtained through the cutting force testing system, and the fluctuation range of F_n, F_t and cutting force F_c under the influence of each factor was obtained through analysis. The research shows that the essence of cutting concrete with cutters was the repeated cycle of collision, cutting, and peeling, and the cutting force was always in a fluctuating state. The rake face played a major role in the rock breaking task, and the required F_n and F_t and their fluctuation decreased with the increase of the rake angle. The cutter with larger rake angle had more obvious pulling and shearing effects on the concrete. The mean value of F_n and F_t had a linear relationship with specimen strength and cutting depth. The larger the specimen strength and cutting depth were, the larger F_n and F_t were, and the smaller the fluctuation in its direction was. The effect of cutting depth on the fluctuation of F_c was greater than that of the specimen strength. The particle size of the debris increased with increasing cutting depth, while the debris at cutter tip was in powder form.