泥水盾构在砂卵石地层掘进时，排浆管道将输送大量大粒径卵石，导致浆体产生不稳定湍流，这给管道压力损失的确定带来了挑战。该研究设计了环流试验装置，以CMC透明黏性浆液为实验用泥浆，建立了基于计算流体动力学与离散单元法（CFD-DEM）耦合的三维数值模型；以粒径为5~80 mm的卵石为对象，分析了卵石粒径级配、浆液流速、卵石体积分数以及管道倾角对管道沿程压力损失的影响规律。研究结果表明：同一卵石粒径级配、卵石体积分数与管道倾角下，管道沿程压力损失随浆液流速的增加大致呈指数函数规律增加；对于水平管道，不同卵石粒径级配下的管道沿程压力损失差别较小；在低浆液流速（v < 2 m/s）下，管道沿程压力损失随卵石体积分数的增大呈线性规律增加，在较高浆液流速（v ≥ 2.0 m/s）下，管道沿程压力损失随卵石体积分数的增大呈指数函数形式增加；对于倾斜及竖直管道，同一卵石粒径级配、卵石体积分数与浆液流速下，管道沿程压力损失随着管道倾斜角度的增大首先表现为缓慢增加，然后呈急剧增加，其转折点的管道倾角为60°。此外，在泥浆浮力以及湍流的作用下，大粒径的卵石难以克服自身重力达到完全悬浮的运动状态，因此，大粒径卵石主要沿管道下壁面运动，且在管道弯头处压力存在明显的分层现象。

During slurry shield tunneling in the sandy pebble stratum, the slurry discharge pipeline will transport a large number of the large irregular pebbles, generating unstable turbulence, which causes difficulties to the determination of the pipeline pressure loss. This study designed a circulating flow test device, and the slurry used in the experiment is CMC transparent viscous slurry. And the study established a numerical model using the computational fluid dynamics-discrete element method (CFD-DEM) coupling approach. Taking pebbles with a particle size of 5~80 mm as the research object, the study investigated the effects of pebble particle size distribution, slurry velocity, pebble volume fraction, and pipeline inclination angle on the pressure loss along the pipeline, respectively. The results indicate that the pressure loss along the pipeline increases exponentially with the increase of slurry velocity under the same particle size distribution, pebble volume fraction, and pipeline inclination angle. And for horizontal pipelines, the effect of pebble particle size distribution on the pressure loss along the pipeline is not significant. In addition, for the low slurry velocity (v < 2 m/s), the pressure loss along the pipeline increases linearly with the increase of pebble volume fraction. And for the high slurry velocity (v ≥ 2.0 m/s), the pressure loss along the pipeline increases exponentially with the increase of pebble volume fraction. For inclined and vertical pipelines, the pressure loss along the pipeline firstly increases slowly with the increase of the pipeline inclination angle, and then increases sharply under the same particle size distribution, pebble volume fraction and slurry velocity, and the pipeline inclination angle at the turning point is 60°. In addition, under the action of mud buoyancy and turbulence, it is difficult for large-size pebbles to overcome their own gravity and reach a state of complete suspension. Therefore, large-size pebbles mainly move along the lower wall of the pipeline, and the pressure at the elbow of the pipeline is obviously stratified.