高磨蚀复合地层盾构刀盘受力分析与计算

Cutterhead Mechanics Analysis of Shield Machine in High Abrasion Complex Stratum

盾构在复合地层中施工,经常会遇到盾构姿态难以控制、刀盘刀具异常或过量磨损、刀盘变形与开裂等问题,目前是盾构施工一大难题。针对芜湖过江隧道其中一段软硬复合地层的工程地质特点,将其在盾构掘进断面内的地层简化为上软下硬的二元地层结构,对刀盘受力公式进行推导并建立刀盘受力计算模型,基于LabVIEW编制盾构刀盘受力计算程序。该程序可以计算盾构机在复合地层掘进过程中的刀盘有效推力、有效扭矩、倾覆力矩和不平衡力及它们的变化情况。最后实例计算,得出刀盘受力和力矩随软岩比、刀盘转角和贯入度的变化规律,解释了盾构在复合地层施工难题的原因,为其提供依据。

Shield construction in composite strata often encounters such problems as difficult control of shield posture,abnormal or excessive wear of cutter head,deformation and cracking of cutter head,which is a major problem in shield construction.In view of the characteristics of the soft and hard complex strata of Wuhu area,the geological section of shield tunneling is simplified as the upper soft and lower hard binary stratum.The force formula of cutter head is deduced and the force calculation model of cutter head is established.Based on LabVIEW,the force calculation program of shield cutter head is compiled.By this new program,the values and changes of these mechanical parameters of cutter head can be obtained,which include effective thrust,effective torque,overturning moment and unbalanced force in shield tunneling in complex stratum.Taking the shield construction of Wuhu Yangtse River Crossing Tunnel for example,the cutter head mechanical state is calculated.Then the variation law of force and moment of cutter head with soft rock ratio,cutter head rotation angle and penetration degree are obtained,and the reasons for the difficulties in shield construction in composite stratum are explained,which provides a basis for it.