基于Mckyes-Ali模型盾构刀具切削软土三维力学模型研究

Three-dimensional Mechanical Analysis on Soft Soil Cutting by Shield Machine Based on Mckyes-Ali Model

为研究盾构法施工过程中任意位置刀具与软土之间的相互作用,基于朗肯被动土压理论,以Mckyes-Ali理论建立的耕作刀具切土阻力模型为基础,考虑切削土与刀具、地层的法向力、黏聚力以及自身重力等,引入表示切刀任意位置的参变量L和Ψ,根据力的平衡原理,建立任意位置刀具的切削软土三维力学模型。最后,通过与已有模型对比,验证了该模型的准确性;通过编制Excel计算界面,保证了该模型工程应用的可行性。该模型适用于盾构任意位置切刀的受力分析,为刀盘刀具的地质适应性设计提供了更加全面的切刀受力计算公式。

In this paper,a three-dimensional（ 3D） mechanical analysis is conducted for soft soil cutting by shield machine,on the basis of Rankine＇s Earth Pressure Theory and Mckyes-Ali cutter resistance model. In this modified Mckyes-Ali model,the cohesion of soils,normal stress imposed by cutter and ground,dead-weight of soil,parameter L and parameter Ψ are taken into account in association with force balance theory. It shows that the modified model is suitable for analysis on stress of any point of the cutter on cutterhead. The modified model is then compared with existing models,and the applicability of the model is verified by using Excel computing interface. The paper can provide suitable formula for the feasibility design of the cutter of shield machine.