基于离散元数值模拟的砂卵石地层盾构掘进刀盘磨损特性研究

砂卵石地层由大量颗粒组成,其本质是离散的、非连续的,属于典型的不稳定地层,颗粒之间孔隙大,无黏聚力,单轴抗压强度普遍较高,刀盘旋转切削时,刀盘与颗粒摩擦非常剧烈,刀盘磨损严重。为研究砂卵石地层盾构掘进刀盘磨损特性,依托兰州市轨道交通1号线,采用颗粒流离散元软件EDEM,研究不同刀盘形式和覆土厚度下盾构机刀具磨损特性。结果表明,刀具磨损不均匀,主要体现在刀盘外围刀具磨损严重,中心处刀具磨损较小。相同掘进参数条件下,辐条式刀盘磨损较小,为面板式的0.7~0.8倍;覆土1.5D(D为盾构机外径)时刀具磨损量约为覆土1 D时的1.15倍。

Study on Cutterhead Wear Characteristics in Shield Tunneling in Sandy Pebble Stratum Based on Discrete Element Numerical Simulation

Sandy pebble stratum is composed of a large number of particles and a typical unstablestratum characterized by discontinuity, non-cohesion, macroporosity and generally high uniaxial compressive strength. Severe friction between the cutterhead and the particles results in serious tool wear when the cutter is working. Based on Lanzhou metro line 1,the law of cutterhead wear in the case of different forms of cutter and covering soil thickness is studied by software EDEM of discrete element numerical simulation. The results show that the wear is inhomogeneous and more severe in the periphery of the cutterhead,and the maximum wear of the spoke shield cutter is 0. 7 ~ 0. 8 times of that of the panel hield cutter,and the tool wear with covering soil thickness 1. 5 D model is about 1. 15 times of that of the 1 D model.